Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(82)
- Akkurt, Nevzat(67)
- Güler, Ömer(66)
- Baskonus, Haci Mehmet(62)
- Bulut, Hasan(60)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(43)
- Yildirim, Numan(42)
- Yildirim, Nuran Cikcikoglu(38)
- Paksoy, Mehmet Yavuz(36)
- Serdar, Osman(36)
- Zengin, Gokhan(36)
- Ince, Muharrem(34)
- Celik, Erkan(33)
- Benzer, Fulya(32)
- Kocabaş, Mehmet(30)
- Sulaiman, Tukur Abdulkadir(30)
- Tanyol, Mehtap(29)
- Yildirim, Ozal(28)
- Aslan, Naim(26)
- Kök, Mediha(26)
- Özkul, İskender(26)
- Ates, Mehmet(25)
- Danabas, Durali(25)
- Kutluyer, Filiz(25)
- Can, Erkan(24)
- Kutlu, Banu(23)
- Onat, Onur(23)
- Demir, Veysel(22)
- Erten, Fusun(22)
- Guler, Omer(22)
- Say, Yakup(22)
- Güler, Seval Hale(21)
- Yaman, Mehmet(21)
- Baykal, Duygu Sen(20)
- Sançar, Taylan(20)
- Susam, Selim Orhun(20)
- Cakilcioglu, Ugur(19)
- Orhan, Cemal(19)
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ1Investigation of Critical Raw Materials in Sludge of Municipal Wastewater Treatment Plant
Topal, Murat; Arslan Topal, E. Işıl
In the present research, lanthanum, vanadium, tungsten, scandium, bismuth, antimony, gallium, phosphorus, magnesium, and cobalt from critical raw materials (CRMs) were monitored for one year in the sewage sludges from an advanced biological wastewater treatment plant with the aim of presentation of possibility of using sewage sludge as a secondary source of critical raw materials. The amounts of the critical raw materials in sewage sludge were calculated annually, and economic values were revealed. Maximum concentrations of lanthanum, scandium, tungsten, bismuth, antimony, gallium, vanadium, cobalt, magnesium, and phosphorus were 4.3, 1.6, 0.5, 1.51, 1.27, 1.7, 23, 5.6, 6500, and 16,170 mg/kg, respectively. In the sewage sludge, the amount of CRMs, which have been formed annually, have been listed as tungsten < scandium < antimony < bismuth < gallium < lanthanum < cobalt < vanadium < magnesium < phosphorus. In autumn, summer, spring, and summer season, the mean highest concentration was for P, while the minimum concentration was for W. In sewage sludge, P and W elements were the highest and the least of the CRMs, respectively. With the recovery of CRMs in sewage sludge, the highest theoric achievable income is for Mg, while the lowest income is for Sb. It is determined that a total of 26,083.8 USD/year could be obtained by recovering the CRMs mentioned here from the sewage sludge.
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İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ3Contamination and Ecological Risk Assessment of Heavy Metals in Surface Sediments of the Munzur Stream, Turkey
Kutlu, Banu
The aim of the present study is to determine the heavy metal concentrations in the surface sediment between 2019-2020 in Munzur Stream,Turkey. The impact of pollution level in the study area was evaluated by geoaccumulation index (Igeo), Contamination Factor (CF), enrichment factor (EF), pollution ecological risk (PER) index, and pollution load index (PLI). The average amount of heavy metals detected in sediment in the study in mg/kg was, in descending order, Fe>Al>Mn>Ni>Cr>Zn >Cu>Pb>Cd>Hg. The data evaluated by several statistical methods indicated that the metals with a positive relationship between them in the Pearson correlation analysis and the elements of the same factor in the factor analysis were mostly the same. The comparison of the results with the sediment quality criteria showed that only the mean value of Mn and Ni exceeded the values of PEL. Heavy metal levels in Munzur Stream sediment exposed to domestic and agricultural wastes, agricultural fertilizers and pesticides, and mines were not high enough to pose a threat to aquatic life.
AtıfScopus9WoS8OpenAlex11İncele - MakaleYalnız künye2023Scopus SJRQ2Computational assesment of Carreau ternary hybrid nanofluid influenced by MHD flow for entropy generation
Ramzan, Muhammad; Ali, Farhan; Akkurt, Nevzat; Saeed, Anwar; Kumam, Poom; Galal, Ahmed M.
Tri-hybrid nano-particles in shear rate-dependent viscous fluid are essential for improving heat and mass transmission in many industries. The current study explores the two-dimensional flow of the Carreau-ternary hybrid nanoliquid with a magnetic field over the stretching surface. The heat transport mechanism is deliberated through the applications of thermal radiation and heat source/sink effects. The entropy minimization of the flow of Carreau ternary hybrid nanofluid has also been scrutinized. Further, the concepts of convective conditions are employed for the numerical solution of the existing model. In the present flow analysis, silver (Ag), Molybdenum disulfide (MoS2), and multi-wall carbon nanotube (MWCNT) nanoparticles are studied. Carboxymethyl cellulose (CMC-water) is used as a base liquid. The well-established numerical collocation finite difference scheme and three-stage Lobatto III as the built-in function of the bvp4c solver via MATLAB have been used to solve the system of equations in the form of concentration, energy, and momentum. Numerous features, such as flow speed, temperature, drag friction, and Nusselt number, are described in figures and tables. From the existing model, some key outcomes are that the rising values of the radiation parameter increased the heat transfer rates. Further, it is dissected that the greater importance of the magnetic field parameter declined the entropy generation and velocity of the liquid.
AtıfScopus88OpenAlex96İncele - MakaleAçık Erişim2023Scopus SJRQ1Radiation mechanism on dissipative ternary hybrid nanoliquid flow through rotating disk encountered by Hall currents: HAM solution
Shamshuddin, M.D.; Akkurt, Nevzat; Saeed, Anwar; Kumam, Poom
The energy transition to enhance heat transport during the flow of ternary hybrid nanofluid comprised of Copper (Cu), Iron oxide (Fe3O4), Silicon dioxide (SiO2) nanoparticles and Polymer as base liquid over a revolving disk surface has been reported. From the several existing techniques, adding nanoparticles to standard working fluids is an effective approach that might dramatically improve the rate of heat transfer. The Hall and radiation impacts are also considered. A mathematical model is developed by assuming the flow as incompressible and purely radial in a cylindrical coordinate system and appropriate similarity variables are introduced for problem simplification and dimensionless analysis. The solution of complex generated PDEs was calculated using semi analytical method known as Homotopy Analysis Method (HAM) after translating them into corresponding ODEs. It has been observed that the consequences of thermal radiation, dissipation term, unsteadiness and rotation parameters boost the energy transmission rate and enhances the heat transfer rate of tri hybrid nanofluids. However, Cu-Fe3O4 nanoparticles in the base fluid remarkably magnifies the energy transmission rate. The unitary ternary hybrid nanofluid (Cu, Fe3O4, SiO2) has higher velocity profiles as compared to unitary nano fluid (Cu) and hybrid nano-fluid (Cu-Fe3O4).
AtıfScopus133WoS121OpenAlex138İncele - MakaleAçık Erişim2023Scopus SJRQ3Evaluation of waste polyethylene terephalate in polyol and polyurethane production
Fırat, Tülay; Kar, Filiz
As technology advances and human population grows, we must meet our diverse needs while minimising harm to the environment. One solution is to prioritise recycling and using second-hand consumer goods. In this study, PET flakes were depolymerised by glycolysis using different molar ratios of glycol such as propylene glycol(PG), triethylene glycol(TEG) and polyethylene glycol(PEG 400) in the presence of two different catalysts: zinc acetate- zinc sulphate. As a result, glycated products (polyols-PO) were obtained. The obtained polyols were then used to synthesise polyurethane films (PU) via acetone process. The thermal and chemical characterisations of the polyurethane films (PU) were analysed. In similar studies, zinc acetate was used as a transesterification catalyst for the glycolysis process. In this study, the same process was carried out using zinc sulphate and zinc acetate. Zinc sulphate was found to be a cheaper and eco-friendlier catalyst alternative to zinc acetate for the glycolysis process.
AtıfOpenAlex1İncele - MakaleYalnız künye2023Scopus SJRQ2Effect of Using Eccentric Braces with Different Link Lengths on the Seismic Demand of CFST Column-Composite Beam Frames Subjected to Near-Field and Far-Field Earthquakes
Etli, Serkan; Güneyisi, Esra Mete
In recent years, in the light of technological developments, the utilization of composite members that enable the use of superior properties of concrete and steel together in earthquake-resistant building design has become widespread. In this study, 5-, 8-, 10-, 13- and 15-story composite moment-resisting framed buildings were designed using composite beams and concrete filled steel tube columns. The effect of using steel braces and the variation of the link length of the eccentric steel braces on the seismic demand of the composite buildings were investigated. For this, eight different cases with braces were considered and compared with the bare structure. The first case had concentric braces (having no link), and the other seven cases had eccentric steel braces with different link lengths classified as short, medium and long. The nonlinear dynamic response of braced and non-braced composite structures was evaluated under the effect of earthquake groups of far-field, near-field with and without pulse effects. Each earthquake group includes ten different ground motion records. SeismoStruct which is a fiber element-based software was used in modeling and analysis of the structures. Seismic behavior of the case studied structures was investigated comparatively through the demand parameters such as the maximum inter-story drift ratios, the maximum roof drift ratios and the deformation states in the structural elements. It was observed that the inclusion of the steel braces provided significant gains in dissipating seismic energy acting through composite buildings and the beam/column deformations decreased considerably, depending on the length of the link and the height of the structure. In some cases, significant damage was monitored in the link members; however, this type of deformation was limited.
AtıfScopus3WoS3OpenAlex18İncele - MakaleYalnız künye2023Scopus SJRQ2Aluminum Recovery by Acid Leaching of Variously Enriched Pyrophyllite Ore: Effects of Pre-treatment Methods for Activation
Aydoğmuş, Ramazan; Erdemoğlu, Murat; Uysal, Turan
Effects of pre-treatment methods such as calcination for thermal activation and intensive milling for mechanical activation on the aluminum (Al) recovery by acid leaching of preliminarily enriched pyrophyllite ore via attrition scrubbing and froth flotation were investigated. XRD patterns of the calcined and the intensively milled samples were compared to determine the changes during the pre-treatment processes. Hot HCl solution was used for dissolution of aluminum to determine the Al recoveries from variously enriched and variously pre-treated pyrophyllite ore samples. Specific thermal and milling energies consumed per unit amount of ore were calculated, and the ideal activation method was suggested by comparing the activation methods in terms of energy consumption. Mechanical activation of the pyrophyllite concentrate obtained by attrition scrubbing rather than froth flotation was suggested for higher recoveries of aluminum from by acidic leaching. It was determined that operating cost (in terms of energy) of the mechanical activation is lower and aluminum recovery is higher than thermal activation. It was concluded that mechanical activation instead of thermal activation is more economical and environmentally friendly method.
AtıfScopus5WoS4OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ3Optimization of shape factor by the response surface method, and the effect on sphalerite flotation recovery
Uysal, T.
Various morphological parameters that affect the flotation recovery of sphalerite were modelled and optimized using the response surface method (RSM). The effects of roughness value, shape factor, and collector concentration were investigated using the central composite full design method. The results were evaluated by analysis of variance. The optimum roughening time was found to be 25 minutes, the optimum roughness value was 2.9071 μm, and the optimum collector concentration was 0.001 M. Using these values, a flotation recovery of 98.01% was obtained. Similarly, in shape factor studies, the optimum grinding time was 15 seconds, the optimum roundness value 0.7421, and the optimum collector concentration 0.0009 M, which resulted in a flotation recovery of 94.30%. The average error between the optimization results and the experimental results was estimated to be less than 6%, and the R2 values were greater than 90%. The study shows that RSM can be effectively applied in finding the economic optimum condition for obtaining maximum flotation recovery with minimum reagent consumption.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2023Scopus SJRQ2A New S-box Generator Algorithm Based on 3D Chaotic Maps and Whale Optimization Algorithm
Artuğer, Fırat
Encryption provides security in cases such as storing confidential information or transmitting it over a network. Today, block cipher algorithms are generally used for encryption. Undoubtedly, one of the most important units of block cipher algorithms to ensure confidentiality is substitution box (s-box) structures. Because s-boxes are nonlinear structures, making the algorithm resistant to differential cryptanalysis. Therefore, the higher the nonlinearity value of the s-box, the stronger it will be. In this study, a new algorithm is proposed to generate s-boxes with high nonlinearity value. In the proposed algorithm, Lorenz and Chua systems, which are 3D chaotic maps, are used for the initial population. The s-boxes produced with these chaotic maps were then increased to 110.5 using the whale optimization algorithm (WOA). WOA is one of the important optimization algorithms developed in recent years and was used for the first time in s-box production in this study. Looking at the results of the analysis, the proposed method has outstripped most of the other existing studies, thanks to effective 3D chaotic maps and WOA.
AtıfScopus44WoS38OpenAlex45İncele - MakaleAçık Erişim2023Scopus SJRQ1Numerical simulation for peristalsis of Quemada fluid: A dynamic mesh approach
Ali, Shahbaz; Nadeem, Sohail; Akkurt, Nevzat; Ali Ghazwani, Hassan; Eldin, Sayed M.
Introduction: Flow dynamics due to the peristaltic pumping has been the topic of great interest for the researchers. But numerical and analytical analyses for the peristaltic motion are limited where flow domain is deformed real-time. Research on peristalsis has a limitation where theoretical aspects of walls motion are considered, neglecting the real time deformation of the walls. Objectives: This paper aims to propose a more reliable and accurate numerical methodology for peristaltic motions to address the above-mentioned challenge. Stream traces, velocities, and pressure drops along the tube is to be visualized more accurately. Methods: In present study a finite volume based dynamic mesh motion method is adopted to analyze the peristaltic motion of a non-Newtonian Quemada fluid in an axisymmetric channel. The walls and interior domain of the channel is dynamically deformed for a sinusoidal wave traveling on boundary. Results: Simulation of unsteady flow behavior for time t=0s to 2s and amplitude ratio Φ=0.2,0.4,and0.6. predicts fluid trapping phenomenon. Rotation of fluid particles is more prominent for higher amplitude ratios. Pressure gradient increases with increasing amplitude ratios. Conclusion: A novel dynamic mesh method is proposed for peristaltic pumping. It provides more accurate and more physical results for stream traces; pressure drops and velocities along the tube. A limited case of the study validates the theoretical and analytical results already presented in literature; hence the method is reliable.
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İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of pea/rice and amylopectin/chromium as an alternative protein source to improve muscle protein synthesis in rats
Ozdemir, Oguzhan; Erten, Fusun; Er, Besir; Orhan, Cemal; Komorowski, James R.; Sylla, Sarah; Perez Ojalvo, Sara; Sahin, Kazim
Background: A preclinical study reported that the combination of an amylopectin/chromium complex (ACr) of branched-chain amino acids (BCAA) significantly enhanced muscle protein synthesis (MPS). This study was conducted to determine the effects of the addition of ACr complex to a pea/rice (PR) protein on MPS, insulin, muslin levels, and the mTOR pathway in exercised rats. Methods: Twenty-four rats were divided into three groups: (i) exercise (Ex); (ii) Ex + PR 1:1 blend (0.465 g/kg BW); (iii) Ex + PR + ACr (0.155 g/kg BW). On the day of single-dose administration, after the animals were exercised at 26/m/min for 2 h, the supplement was given by oral gavage. The rats were injected with a bolus dose (250 mg/kg BW, 25 g/L) of deuterium-labeled phenylalanine to determine the protein fractional synthesis rate (FSR) one h after consuming the study product. Results: The combination of PR and ACr enhanced MPS by 42.55% compared to the Ex group, while Ex + PR alone increased MPS by 30.2% over the Ex group (p < 0.0001) in exercised rats. Ex + PR plus ACr significantly enhanced phosphorylation of mTOR and S6K1 (p < 0.0001), and 4E-BP1 (p < 0.001) compared to the Ex (p < 0.0001). PR to ACr also significantly increased insulin and musclin levels (p < 0.0001) in exercised rats. Additionally, compared to Ex + PR alone, Ex + PR + ACr enhanced mTOR (p < 0.0001) and S6K1 (p < 0.0001) levels. Conclusion: These data suggested that PR + ACr may provide an alternative to animal proteins for remodeling and repairing muscle by stimulating MPS and mTOR signaling pathways in post-exercised rats. More preclinical and clinical human studies on combining pea/rice and amylopectin/chromium complex are required.
AtıfScopus4OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ2Unraveling the chemical profile, antioxidant, enzyme inhibitory, cytotoxic potential of different extracts from Astragalus caraganae
Kurt-Celep, İnci; Zengin, Gokhan; Uba, Abdullahi I.; Caprioli, Giovanni; Mustafa, Ahmed M.; Angeloni, Simone; Cakilcioglu, Ugur; Guler, Osman; Kaplan, Alevcan; Sharmeen, Jugreet
Six extracts (water, ethanol, ethanol-water, ethyl acetate, dichloromethane, and n-hexane) of Astragalus caraganae were studied for their biological activities and bioactive contents. Based on high-performance liquid chromatography-mass spectrometry (HPLC-MS), the ethanol-water extract yielded the highest total bioactive content (4242.90 µg g−1), followed by the ethanol and water extracts (3721.24 and 3661.37 µg g−1, respectively), while the least total bioactive content was yielded by the hexane extract, followed by the dichloromethane and ethyl acetate extracts (47.44, 274.68, and 688.89 µg g−1, respectively). Rutin, p-coumaric, chlorogenic, isoquercitrin, and delphindin-3,5-diglucoside were among the major components. Unlike the dichloromethane extracts, all the other extracts showed radical scavenging ability in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay (8.73–52.11 mg Trolox equivalent [TE]/g), while all extracts displayed scavenging property in the 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assay (16.18–282.74 mg TE/g). The extracts showed antiacetylcholinesterase (1.27–2.73 mg galantamine equivalent [GALAE]/g), antibutyrylcholinesterase (0.20–5.57 mg GALAE/g) and antityrosinase (9.37–63.56 mg kojic acid equivalent [KAE]/g) effects. The molecular mechanism of the H2O2-induced oxidative stress pathway was aimed to be elucidated by applying ethanol, ethanol/water and water extracts at 200 µg/mL concentration to human dermal cells (HDFs). A. caraganae in HDF cells had neither a cytotoxic nor genotoxic effect but could have a cytostatic effect in increasing concentrations. The findings have allowed a better insight into the pharmacological potential of the plant, with respect to their chemical entities and bioactive contents, as well as extraction solvents and their polarity.
AtıfScopus31OpenAlex36İncele - MakaleAçık Erişim2023Scopus SJRQ1Safe-haven and hedging roles of precious metals for BRICS and Turkey
Gençyürek, A. Galip; Ekinci, Ramazan
This paper investigates the role of precious metals in risk management (diversification, hedging, safe haven, leading and lagging roles) in the stock markets of BRICS-T (Brazil, Russia, India, China, South Africa, and Turkiye) countries using DCC-IGARCH-t-copula (Dynamic Conditional Correlation Integrated Generalized Autoregressive Conditional Heteroscedasticity - t-copula) and rolling Hong causality with daily data from the period 2015 to 2022. Our empirical findings indicate that, despite the existence of bidirectional variance causality, precious metals (gold, silver, platinum, and palladium) are effective risk management instruments, except for hedging. Moreover, to mitigate risk during the COVID-19 pandemic, investors should increase the weight in their portfolios of precious metals, except for gold. The leading role of precious metals in variance causality can help policy makers to design appropriate policies for curbing market vulnerability.
AtıfScopus14WoS14OpenAlex17İncele - MakaleYalnız künye2023Scopus SJRQ1Laboratory evaluation of oak ash waste for use in hot mix asphalt modification
Geçkil, Tacettin; Beyza İnce, Ceren; Aksağan, Zülfükar
In this study, the effect of Oak Ash (OA), a biomass waste, on the mechanical properties of hot mix asphalt (HMA) was investigated and its usability in road engineering was evaluated. For this purpose, firstly, various physical and chemical properties of B70/100 penetration class pure asphalt, OA and crushed limestone aggregate were determined. Then, the optimum asphalt content (OAC) of the mixture was determined according to the Marshall mix design method using aggregate and pure asphalt. Based on this determined content, pure and OA added (1%, 2%, 4% and 6% by weight of asphalt) modified hot mix specimens were prepared. Pure and OA added modified mixture specimens were subjected to Marshall stability, indirect tensile strength (ITS), moisture damage, indirect tensile stiffness modulus (ITSM), static-dynamic creep and calorie tests. According to the results obtained, it has been determined that the OA additive has an improving effect on all mechanical properties of the mixtures, especially on the permanent deformation resistance at high temperatures. It is considered that the use of this additive at a rate of 2% in the hot mixture can increase the resistance of the pavement against deterioration and reduce the maintenance and repair costs of the road.
AtıfScopus26WoS25OpenAlex24İncele - DüzeltmeAçık Erişim2023Scopus SJRQ1Corrigendum to “Modeling and numerical simulation of non-Newtonian arterial blood flow for mild to severe stenosis” [Alex. Eng. J. 72 (2023) 195–211, (S1110016823002594), (10.1016/j.aej.2023.03.088)]
Nadeem, Sohail; Ali, Shahbaz; Akkurt, Nevzat; Bechir Ben Hamida, Mohamed; Almutairi, Shahah; Ghazwani, Hassan Ali; Eldin, Sayed M.; Khan, Zareen A.; Al-Shafay, A.S.
The authors regards, In the original article, in Ref. [16], the citation was incorrectly stated as: H. Liu et al., 3D printing of artificial blood vessel: study on multi-parameter optimization design for vascular molding effect in alginate and gelatin, Micromachines (2017) 8. However, upon thorough review and verification, the authors have discovered that the correct citation should be as follows: V. Carvalho, N. Rodrigues, R. Ribeiro, P.F. Costa, R.A. Lima, S.F.C.F. Teixeira, 3D printed biomodels for flow visualization in stenotic vessels: An experimental and numerical study, Micromachines, vol. 11, no. 6, doi: 10.3390/mi11060549. The authors deeply apologize for this oversight and any confusion it may have caused to the readers and the scholarly community. It is crucial to ensure the accuracy and integrity of their citations, and they sincerely regret any inconvenience this may have caused.
- MakaleAçık Erişim2023Scopus SJRQ1Yield and Composition of the Essential Oil of the Opopanax Genus in Turkey
Babacan, Ebru Yüce; Demirpolat, Azize; Çakılcıoğlu, Uğur; Bagcı, Eyüp
The genus Opopanax W. Koch (Apiaceae) is represented by four species in Turkey. The composition of the essential oil of Opopanax genus members (Apiaceae) growing in Turkey was investigated in this study. GC-MS was used to analyze the composition of Opopanax essential oil samples that were taken from their natural environments. The Clevenger apparatus was used to hydrodistill the plant’s aerial parts, and the yields were determined to be between 0.2% v/w (for O. siifolius) and 0.4% (for O. hispidus, O. chironium, and O. persicus). The results and the chemical data provided some information and clues on the chemotaxonomy of the genus Opopanax. In this study, γ-elemene, butanoic acid octyl ester, and cylopropane were the main compounds identified in the essential oils of O. chironium, O. hispidus, and O. persicus. In particular, hexynyl n-valerate was most abundant in the essential oil of O. chironium, cyclopropane in that of O. hispidus, γ-elemene in that of O. persicus, and n-hexadecanoic acid/palmitic acid in that of O. siifolius. In a chemotaxonomic approach, the essential oil analysis of the Opopanax species revealed that these species conformed in a cluster analysis with their morphological classification. The constituents of the essential oils of all examined in the genus Opopanax were determined in this study, which is the most thorough one to date. This study provides new information about the composition of the essential oils of the investigated species.
AtıfScopus4WoS4İncele - MakaleYalnız künye2023Scopus SJRQ1Modeling the form, distribution and paleoclimatic implications of former glaciers in the Teke Peninsula (Eastern Mediterranean, Turkey)
Keserci, Ferhat; Bayrakdar, Cihan; Çılğın, Zeynel; Evans, Ian S.
The Western Taurus Mountains on the Teke Peninsula, Southwestern Turkey, saw substantial glaciation in the late Quaternary period. Accurate reconstructions of former glacier extent in this relatively marginal area of glaciation are important for establishing the paleoclimate in the Eastern Mediterranean Basin. From west to east, the mountains of Sandıras, Karadağ, Akdağ (Kaş), and Beydağları preserve clear evidence of cirques and moraines, representing glacial valley land systems. This study used calculation tools for Glacier Reconstruction, (GlaRe) and Equilibrium Line Altitude (ELA), with glacier outlines based on the geomorphological evidence and Digital Elevation Models (DEMs), to determine the distribution and ELAs of former glaciers and to estimate paleotemperature and paleo-precipitation during the maximum ice extent. The results are analyzed at three scales: for each glacier, between glaciers and between mountain ranges. While the glaciation was at its peak, we estimate that glaciers covered a total area of 26.4 km2 (1.28 ± 0.08 km2 on Sandıras Mountain, 3.86 ± 0.23 km2 on Karadağ, 16.17 ± 0.970 km2 on Akdağ (Kaş), and 5.09 ± 0.30 km2 in Beydağları): the longest glacier was in Akdağ (Kaş) with a length of 5787 m. Average paleo-ELA (pELA) was calculated as 2077 m a.s.l in Sandıras, 2097 m a.s.l in Karadağ, 2565 m a.s.l in Akdağ (Kaş), and 2468 m a.s.l in Beydağları. Glacier modeling estimated that the maximum ice thickness in Akdağ was 240 m ± 14, and the average thickness 75 ± 4 m. Among these mountains, Karadağ had the lowest elevation to which glaciers descended (1760 ± 16 m a.s.l). Topographic analyses revealed that glaciers formed in the four mountains mostly in the North-facing localities with highest slope values of 18 to 30°. During the maximum glaciation period air temperature depression has been estimated as 8 to 9° Celsius; That required a precipitation increase of some 40 to 60 % compared to present, to produce the former glaciers mapped in the Teke Peninsula.
AtıfScopus10WoS9OpenAlex17İncele - MakaleYalnız künye2023Scopus SJRQ1A novel two-phase group decision-making model for circular supplier selection under picture fuzzy environment
Kaya, Sema Kayapinar
Circular supply chain management (CSCM), which incorporates circular thinking into supply chain management, promotes supply chain sustainability by offering a novel and compelling viewpoint. In the CSCM, supplier selection is crucial in establishing a competitive edge among businesses by decreasing environmental degradation and related supply chain expenses. This paper aims to propose a novel two-phase group decision-making approach, which combines the picture fuzzy Analytical Hierarchical Process (PF-AHP) and grey Measurement of Alternatives and Ranking According to Compromise Solution (MARCOS-G) model to select railway material suppliers within the scope of circular economy perspective. In group decision-making, a picture fuzzy number-based approach aggregates individual decision makers’(DMs) opinions and provides a lower level of computing complexity and a higher level of performance. The PF-AHP has been used to produce the weights of the criteria, and the MARCOS-G technique has been used to rank the suppliers and choose the most appropriate one. The results and verification of the novel method are carried out throughout a comprehensive sensitivity analysis. For this purpose, 50 scenarios with changes in the weight values of criteria were developed. In the validation analysis, a comparison with other grey COPRAS, TOPSIS, ARAS and WASPAS methods were performed. Due to the ranking results obtained from Spearman’s correlation analyses, the MARCOS-G is almost consistent and it can be seen that the A4 remains the top supplier in all 50 scenarios.
AtıfScopus34WoS30OpenAlex39İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ1Geochemical and radiometric data for mafic rocks from the Guleman Ophiolite (SE, Turkey): New insights on the geodynamic evolution of the southern Neo-Tethyan ocean
Sapancı, Özgür; Tokat, Gürkan; Eraslan, Nuh Kadri; Karakaya, Abdullah Onur; Gücer, Mehmet Ali; Çimen, Okay
The Guleman Ophiolite is located in the southeast of Turkey and mainly consists of harzburgites and dunites hosting economically viable chromitite bodies, and lesser amounts of cumulate and isotropic gabbro, diabase dykes, pyroxenite and locally plagiogranite. This study reports the combined whole-rock geochemical and radiogenic isotope (Sr and Nd) data for gabbro and diabase dykes, and in-situ zircon U-Pb geochronological data for plagiogranite and gabbro from the Guleman Ophiolite. Two different geochemical groups were determined based on immobile minor and trace elements, and radiogenic isotope characteristics of gabbro and diabase dykes investigated here. The first group is represented by boninites and displays highly depleted elemental patterns compared to NMORB, and spoon-shaped rare earth element profiles. Contrarily, the second group resembles back-arc basin basalts and is characterized by NMORB-like rare earth element patterns associated with negative Nb anomalies. The boninitic samples are characterized by less radiogenic 143Nd/144Nd(i) (0.51229 to 0.51267; ƐNd = −4.8 to +2.7) and more radiogenic 87Sr/86Sr(i) (0.70549 to 0.70758) isotope compositions compared to the back-arc basin basalt-like samples (143Nd/144Nd(i) = 0.51289 to 0.51296; ƐNd = +7.0 to +8.4; 87Sr/86Sr(i) = 0.70496 to 0.70629), indicating derivation from distinct and/or heterogeneous mantle source regions within a supra-subduction zone. The LA–ICP–MS zircon U-Pb analyses yielded concordant late Cretaceous ages for gabbro (82 ± 2.9 Ma) and plagiogranite (79.9 ± 0.8 Ma) samples. The overall geochemical, isotopic and geochronological data presented here suggest that the Guleman Ophiolite consists of forearc and initial back-arc spreading sections of oceanic crust, which may have been formed in an intra-oceanic subduction zone within the Berit Ocean (northern branch of the southern Neo-Tethyan ocean). Moreover, the generation of continental arc magmatism (i.e. Baskil and Esence Granitoids) was well-documented on the active margin of the Malatya-Keban Metamorphics to the north. Therefore the closure of this oceanic basin should have resulted in multiple coeval northward subduction events during the late Cretaceous.
AtıfScopus8WoS7OpenAlex9İncele - MakaleYalnız künye2023Scopus SJRQ2Chemical Characterization of Different Extracts from Artemisia annua and Their Antioxidant, Enzyme Inhibitory and Anti-Inflammatory Properties
Acquaviva, Alessandra; Nilofar; Bouyahya, Abdelhakim; Zengin, Gokhan; Di Simone, Simonetta Cristina; Recinella, Lucia; Leone, Sheila; Brunetti, Luigi; Uba, Abdullahi Ibrahim; Cakilcioğlu, Ugur
Artemisia annua L. (Asteraceae Family) is an important plant in Asia that has been used for treating different diseases, including fever due to malaria, wounds, tubercolisis, scabues, pain, convulsions, diabetes, and inflammation. In this study we aimed to evaluate the effects of different polarity extracts (hexane, dichloromethane, ethyl acetate, ethanol, ethanol/water (70 %) and water) from A. annua against the burden of inflammation and oxidative stress occurring in colon tissue exposed to LPS. In parallel, chemical composition, antiradical, and enzyme inhibition effects against α-amylase, α-glucosidase, tyrosinase, and cholinesterases were evaluated. The water extract contained the highest content of the total phenolic with 34.59 mg gallic acid equivalent (GAE)/g extract, while the hexane had the highest content of the total flavonoid (20.06 mg rutin equivalent (RE)/g extract). In antioxidant assays, the polar extracts (ethanol, ethanol/water and water) exhibited stronger radical scavenging and reducing power abilities when compared to non-polar extracts. The hexane extract showed the best AChE, tyrosinase and glucosidase inhibitory effects. All extracts revealed effective anti-inflammatory agents, as demonstrated by the blunting effects on COX-2 and TNFα gene expression. These effects seemed to be not related to the only phenolic content. However, it is worthy of interest to highlight how the higher potency against LPS-induced gene expression was shown by the water extract; thus suggesting a potential phytotherapy application in the management of clinical symptoms related to inflammatory colon diseases, although future in vivo studies are needed to confirm such in vitro and ex vivo observations.
AtıfScopus45OpenAlex43İncele