Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Acet, Tuba(4)
- Aydınçakır, Emre(4)
- Kaygusuz, Abdullah(4)
- Sukuroglu, Ebru Emine(4)
- Baltacı, Cemalettin(3)
- Dessureault, Sean(3)
- Kankal, Murat(3)
- Karpuz, Ömer(3)
- Kurt, Kemal(3)
- Totik, Yasar(3)
- Yücel, Cem(3)
- Şan, Murat(3)
- Aksüt, Yavuz Selim(2)
- Akçay, Fatma(2)
- Ar, Ilker Murat(2)
- Cicerali, Derya(2)
- Duran, Celal(2)
- Efeoglu, Ihsan(2)
- Erol, Ismail(2)
- Günen, Mehmet Akif(2)
- Gürdal Limon, Elif(2)
- Jeong, Youn-Joong(2)
- Kahraman, M. Mustafa(2)
- Kurnaz, Muammer(2)
- Kurt, Pınar(2)
- Limon, Onur(2)
- Ozdes, Duygu(2)
- Oztel, Ahmet(2)
- Peker, Iskender(2)
- Rogers, W. Pratt(2)
- Saydam Eker, Çiğdem(2)
- Sukuroglu, E.E.(2)
- Sukuroglu, Suleyman(2)
- Totik, Y.(2)
- Vural, Alaaddin(2)
- Yetgin, Şükrü(2)
- Yi, Keewook(2)
- Yılmaz, Hacı Ömer(2)
- Çullu, Mustafa(2)
- İlyasoğlu, Huri(2)
Yayınlar
- MakaleYalnız künye2021Effects of graphene oxide addition on wear behaviour of composite coatings fabricated by plasma electrolytic oxidation (PEO) on AZ91 magnesium alloy
Kucukosman, Rıdvan; Sukuroglu, Ebru Emine; Totik, Yasar; Sukuroglu, Suleyman
Graphene oxide (GO) integrated composite coatings were deposited on AZ91 magnesium alloys by the PEO (Plasma Electrolytic Oxidation) and the treatment which has a post-PEO hydrothermal process. For the first group samples, PEO was performed in the silicate/phosphate-based electrolyte including 5–10 µm in size the GO particles synthesized using the Tour Method. For the second group samples, after PEO treatment, the post-PEO hydrothermal process was carried out in the oven in the GO-distilled water mixture containing GO produced with the same protocol. The effects of GO on wear behavior, structural and morphological features of composite coatings were examined with a pin-on-disc tribometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy, respectively. The results showed that the addition of GO improved significantly the adhesion to the substrate material of composite coatings, increased the coating thickness and hardness. Post-PEO hydrothermal process resulted in the formation of partial a thin solid lubricant GO film on the surface of composite coatings and thus exhibited the best wear and friction resistance.
- MakaleYalnız künye2021Investigation of characterization and tribological behavior of composite oxide coatings doped with h-BN and graphite particles on ZA-27 alloy by micro-arc oxidation
Kaplan, Erdar; Sukuroglu, Ebru Emine; Cuvalci, Olkan
This paper investigates the tribological effects of composite oxide coatings grown on ZA-27 surfaces under dry sliding condition. Coating processes were conducted using three different electrolytic solutions through micro-arc oxidation (MAO) method. The base electrolytic solution without any particles as additives was labeled as MAO-Coated, whereas electrolytic solution labeled as Coated-A contained graphite particles and Coated-B contained hexagonal boron nitride (h-BN) particles incorporated into base solution. The morphology of each coated samples were analyzed using a Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). The friction and wear tests were conducted using a pin-on-disc tester in order to evaluate the tribological behavior. Results indicated the friction coefficients of both Coated-A and Coated-B samples were lower when compared to that of uncoated ZA-27 alloy. Further comparative studies showed Coated-A samples containing graphite particles resulted in the lowest friction coefficient.
- MakaleYalnız künye2021Modification of the random differential transformation method and its applications to compartmental models
Bekiryazici, Zafer; Merdan, Mehmet; Kesemen, Tulay
In this study, a modification of the random differential transformation method is given by using Laplace-Padé method. The modification, which has previously been introduced for the deterministic differential transformation method (DTM), is used to obtain improved approximate expected values, variances, and confidence intervals for systems of random differential equations. Comparison of approximate results obtained from the random differential transformation method and the modified method are given to underline the improvement of the approximations. Epidemiological compartmental models of type SIR and SIIR are used to implement the modified method and demonstrate its advantages. Simulations and deterministic counterparts of the models are also investigated to confirm the suitability of the results of the approximations.
- MakaleYalnız künye2020Effects of voltage on the components of surface integrity of Al2O3 ceramic coatings on AA2024 by plasma electrolytic oxidation
Matin, Reza; Totik, Yasar; Sukuroglu, Ebru Emine; Efeoglu, Ihsan; Santos, Telmo G.
It is said that plasma electrolytic oxidation (PEO) is considered as an effective technique to boost the surface properties of light materials by means of forming ceramic films on their surfaces. In this study, three different voltage values were applied to the PEO process to AA2024 so that Al2O3 ceramic coatings were directly supplied for AA 2024 substrates by PEO and it is focused on the adhesion of interface between coating and substrate. All of the cases such as microstructure, phase composition, thickness, roughness and hardness of Al2O3 ceramic coatings were assayed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Atomic-force microscopy (AFM), Eddy Current Non-destructive testing and microhardness test, respectively. The results showed that roughness, hardness and thickness of the coatings were increased as we increased the voltage. Therefore, it could be claimed that the voltage parameters have an important role in the unified coating on the metal surface as it is directly connected with the morphologies of the PEO coating.
- MakaleYalnız künye2020Reading comprehension, Mathematics self-efficacy perception, and Mathematics attitude as correlates of students’ non-routine Mathematics problem-solving skills in Turkey
Öztürk, Mesut; Akkan, Yaşar; Kaplan, Abdullah
Literature that investigates the factors affecting problem-solving evaluates the cognitive and affective components, such as reading comprehension, metacognition, Mathematics anxiety, Mathematics attitude and Mathematics self-efficacy. Recently, studies have shown that Mathematics attitude and Mathematics self-efficacy as affective factors, and reading comprehension as a cognitive factor could play a crucial role in the problem-solving of middle school students. This study investigated the influence of reading comprehension skill, Mathematics self-efficacy perception and Mathematics attitude on non-routine Mathematics problem-solving skills. It is hypothesized that non-routine problem-solving skills are related to reading comprehension skills, Mathematics self-efficacy perception and Mathematics attitudes. To achieve this aim, a reading comprehension skill test, a Mathematics self-efficacy perception scale, a Mathematics attitude scale and a non-routine problem-solving skill test were applied. The instruments were completed by 362 middle school students. A correlation analysis was used to determine the relationship of variables on non-routine problem-solving skills, and the predictive effects of the predictor variables on non-routine Mathematics problem-solving skills were examined by hierarchical regression analysis. The analysis also showed that for middle-school students’ non-routine Mathematics problem-solving skills, all related factors–reading comprehension, Mathematics self-efficacy perception and Mathematics attitude were significant. Reading comprehension skills and Mathematics self-efficacy perception significantly predicted problem-solving skills, and both predictors explained a total of 22% of the total variance.
- MakaleYalnız künye2020Hazard analysis using a Bayesian network and linear programming
Efe, Burak; Kurt, Mustafa; Efe, Ömer Faruk
In order to make a system safer, it is necessary to determine which hazard should be removed by considering the interactions of all hazards in the process. In this study, the influence of the hazards related to iron works in a construction firm is examined by Bayesian network approach. If only the most important hazard is identified and removed from the work environment, it may be erroneous to comment on the levels of the remaining hazards. A Bayesian network is proposed to remove this problem. If there is more time and budget than planned for a process, these capacities will have to be reduced in other processes. Linear programming is proposed to remove this problem. A strong decision support system has been established by combining a Bayesian network and linear programming. A construction firm application has been demonstrated using the proposed method.
- MakaleYalnız künye2020Bottleneck identification and ranking model for mine operations
Kahraman, M. Mustafa; Rogers, W. Pratt; Dessureault, Sean
Mining has a long history of production and operations management. Considering the increasing complexity of reserves, declining metal grades, and worldwide price volatilities, mines have to operate more efficiently than ever. In recent years, companies have been adopting innovative solutions and technologies to reduce costs and remain competitive in the global market. Specifically, management of bottlenecks has been in the focus of the manufacturing industry for decades now. The mining industry has made significant advancements in process improvement tools using equipment, human, and asset tracking capabilities. However, to date, there is no holistic approach or system to identify and manage the bottleneck in the entire value chain of mining. This research proposes a new method to identify and rank the bottlenecks in a mine value chain. The method is applied in a coal mine and the results are presented in the case study.
- MakaleAçık Erişim2020Response of Japanese quails (Coturnix coturnix japonica) to dietary inclusion of Moringa oleifera essential oil under heat stress condition
Tekce, Emre; Bayraktar, Bülent; Aksakal, Vecihi; Dertli, Enes; Kamiloğlu, Aybike; Çinar Topcu, Kübra; Takma, Çiğdem; Gül, Mehmet; Kaya, Hacer
The present study was aimed at investigating the effects of the dietary use of different doses of Moringa oleifera essential oil (MOEO) on performance parameters, internal organ weights and meat quality in Japanese quails (Coturnix coturnix japonica) exposed to Heat Stress (HS). For this purpose, 320 male day-old quail chicks were used. Seven days of preliminary (physical exercise) and a 35-day fattening period were applied. The animals were divided into 8 groups, each including 40 animals according to temparature (C: 25 °C and SC: 37 °C) and dietary doses (C, 200, 400 and 600). Each group was divided into 4 subgroups, each comprising 10 animals. The consequences of this study showed that, in the stress-free (HSF) groups, while all of the different doses of dietary MOEO positively affected growth performance, feed intake and feed efficiency, in the HS groups, similar positive effects were observed with the use of 200 ppm of dietary MOEO. While no effect was detected on internal organ weights on Days 21 and 42 in the HSF and HS groups, a dose-dependent increase was determined in the intestinal pH value on day 42 in the HS group (p <.05). Additionally, in the analysis of meat quality on the 21st and 42 days compared to the controls, no effect was observed on the meat colour parameters value and TBARS level in the HS and HSF groups. Based on the consequences of this study, it is considered that, MOEO could be used as an alternative product in poultry, at a dose of 200 ppm, to reduce the detrimental effects of HS.HIGHLIGHTS Temperature stress, performance parameters and serious problems in the health of poultry. Moringa olifera helps regulate performance parameters in poultry exposed to heat stress. Since the addition of Moringa oleifera to the diets does not affect the organ weight and meat quality in 21 and 42 days, it does not cause any negative effects for the consumer.
- MakaleYalnız künye2019Exploring the value of using data: a case study of continuous improvement through data warehousing
Rogers, W. Pratt; Kahraman, M. Mustafa; Dessureault, Sean
The mining industry is adapting data-rich technology. Data management processes and infrastructure require additional investment which, can be difficult to justify. A valuation model for data management infrastructure would necessitate modelling the ‘use’ of data and quantifying the value and the likelihood of success of improvement initiatives. A model is presented which can assess the impacts of a data-driven initiative. The initiatives are shown to be the foundation of improved shift coordination resulting in significant and sustained operational improvements. This paper aims to illustrate the value of using data from source systems in mining operations.
- MakaleYalnız künye2018Induced simplified neutrosophic correlated aggregation operators for multi-criteria group decision-making
Şahin, Rıdvan; Zhang, Hong-yu
Induced Choquet integral is a powerful tool to deal with imprecise or uncertain nature. This study proposes a combination process of the induced Choquet integral and neutrosophic information. We first give the operational properties of simplified neutrosophic numbers (SNNs). Then, we develop some new information aggregation operators, including an induced simplified neutrosophic correlated averaging (I-SNCA) operator and an induced simplified neutrosophic correlated geometric (I-SNCG) operator. These operators not only consider the importance of elements or their ordered positions, but also take into account the interactions phenomena among decision criteria or their ordered positions under multiple decision-makers. Moreover, we present a detailed analysis of I-SNCA and I-SNCG operators, including the properties of idempotency, commutativity and monotonicity, and study the relationships among the proposed operators and existing simplified neutrosophic aggregation operators. In order to handle the multi-criteria group decision-making (MCGDM) situations where the weights of criteria and decision-makers usually correlative and the criterion values are considered as SNNs, an approach is established based on I-SNCA operator. Finally, a numerical example is presented to demonstrate the proposed approach and to verify its effectiveness and practicality.
- MakaleYalnız künye2018Investigation of high temperature wear resistance of TiCrAlCN/TiAlN multilayer coatings over M2 steel
Sukuroglu, E.E.; Baran, O.; Totik, Y.; Efeoglu, I.
In this study, TiCrAlCN/TiAlN multilayer coatings were deposited on M2 high speed steel substrates by the Closed-Field Unbalanced Magnetron Sputtering system. The chemical composition, microstructure, morphology, mechanical and high temperature wear resistance properties of the coatings were characterized, analyzed and compared to the substrate. The high temperature wear tests were carried out under a load of 2 N at the lap (wear test distance) of 50 m and in dry sliding condition at Room Temperature (RT), 150, 300, 450, and 600 °C on atmospheric conditions. It has been found that the TiCrAlCN/TiAlN multilayer coatings have a higher wear resistance than the M2 substrate. The stable friction behavior and low friction tendency was determined at 600 °C. When the test temperature increased, the wear rates decreased. Narrow and smooth wear tracks and also the lowest wear rate were obtained at 600 °C.
- MakaleYalnız künye2018Increasing adherence to mine plan through data integration and process change
Kahraman, Muhammet Mustafa; Dessureault, Sean
This paper focuses on the development of a decision support element to control real-time adherence to mine plan within a control room environment. This system, known as a mine planning screen (MPL), integrates mine planning and production processes. The key inputs are production data tracked by the fleet management system and mine plans entered by mine planners into spreadsheets. The data are integrated with the use of database query languages and MPL charts are displayed in a web environment. The MPL screen displays two types of information: real-time adherence to plan by pit and historical adherence by crews. The objective of the screen is to increase adherence to the overall plan, a key part of a larger real-time blending initiative. This research discusses the technical development of the new tool, its deployment and peer pressure technique for user motivation.
- MakaleYalnız künye2018An enhanced scanning-based MPPT approach for DMPPT systems
Başoğlu, Mustafa Engin
In this paper, an improved maximum power point tracking (MPPT) approach being low parameter dependency, simple structure and limited search interval has been presented for distributed MPPT photovoltaic (PV) systems. Basically, this approach is based on scanning of power–voltage (P-V) characteristic curve of PV modules in a limited duty ratio interval which makes tracking operation simple, fast and efficiently available in both uniform irradiance and partial shading conditions (PSCs). By limiting the scanning interval of maximum and minimum values of duty ratio via some analyses related to P-V characteristic for PSCs, global MPPT (GMPPT) is achieved in an efficient way. So as to validate performance of the proposed approach, a single-ended primary inductance converter has been used in both simulation and experimental studies. PV simulator has been used as a PV source to obtain different module characteristics with different number of bypass diodes and PV power levels. Both simulation and experimental results clarify that improved MPPT approach realises GMPPT effectively. Due to the high performance results, this approach can be an alternative technique in module-integrated converters, smart modules and PV power optimisers in which single module is used.
- MakaleYalnız künye2017Radioactivity measurements and risk assessments of spa waters in some areas in Turkey
Duran, Selcen Uzun; Kucukomeroglu, Belgin; Damla, Nevzat; Taskin, Halim; Celik, Necati; Cevik, Uğur; Ersoy, Hakan
The current study presents the results of the activity of radionuclides in spa waters, and evaluates their radiological influences on the population consuming these waters in the Central and Eastern Black Sea regions of Turkey. Since these waters are used for therapy and consumption purposes unconsciously, their radiological impact on the people was computed by taking into consideration the annual intake through ingestion of 226Ra, 232Th, 40K, 137Cs and 222Rn. The mean activities were estimated to be 11.35 for gross alpha, 6.23 for gross beta, 2.96 for 226Ra, 0.42 for 232Th, 0.069 for 137Cs, 0.19 for 40K, and 267 Bq L–1 for 222Rn, respectively. The estimated effective doses from spa water were found to be 49.77 µSv a–1 (226Ra), 5.95 µSv a–1 (232Th), 0.07 µSv a–1 (137Cs), 0.83 µSv a–1 (40K) and 56.03 µSv a–1 (222Rn). These values were evaluated and compared with related verified values from literature. Also, physico-chemical characterizations of spa water samples considered in the current study were investigated. This study would be useful for consumers and official authorities for the assessment of radiation exposure risk due to usage of the considered spa waters.
- MakaleAçık Erişim2017Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction
Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin
In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L) Cl2]·2H2O (1), [Co(L)Cl2(H2O)2] (2) and [Ni(L)Cl2(H2O)2] (3), having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1. The esterification of butanol gave butyl acetate with 100% selectivity.
- MakaleYalnız künye2017The effect of plasma electrolytic oxidation process parameters on the tribocorrosion properties of TiO2 coatings
Sukuroglu, Ebru Emine; Farzi, Hamed; Sukuroglu, Suleyman; Totik, Yasar; Arslan, Ersin; Efeoglu, Ihsan
Despite the fact that Titanium and its alloys are materials which have excellent corrosion-resistant properties, they have poor wear and friction performance under tribological conditions. The aim of this study is to find suitable parameters for the surface treatment of Cp-Ti substrates which are used under saline environment. In this study, TiO2 coatings were grown on Cp-Ti substrates at different frequencies which are parameters of the coating process. Due to its low cost and ability to achieve high thicknesses, The Plasma Electrolytic Oxidation (PEO) method was applied to grow TiO2 coatings. The microstructures, morphology, and crystallographic structure were analyzed using SEM and XRD. Tribocorrosion properties of the coatings were investigated using a combination of the pin-on-disk wear test and potentiodynamic polarization test units. The frequency is known to have a strong impact on the PEO process. The impacts of frequency changes on the PEO coating performance were examined under a constant voltage. As result, the increase of the frequency caused smaller pores and cracks in the surface morphology of the coating and at the same time this yielded an increment on the tribocorrosion behavior of the coating.
- MakaleAçık Erişim2016Subduction-related Late Cretaceous high-K volcanism in the Central Pontides orogenic belt: constraints on geodynamic implications
Aydınçakır, Emre
Mineral chemistry, major and trace elements, 40Ar/39Ar age and Sr–Nd–Pb isotopic data are presented for the Late Cretaceous Hamsilos volcanic rocks in the Central Pontides, Turkey. The Hamsilos volcanic rocks mainly consist of basalt, andesite and associated pyroclastics (volcanic breccia, vitric tuff and crystal tuff). They display shoshonitic and high-K calc-alkaline affinities. The shoshonitic rocks contain plagioclase, clinopyroxene, alkali feldspar, phlogopite, analcime, sanidine, olivine, apatite and titanomagnetite, whereas the high-K calc-alkaline rocks contain plagioclase, clinopyroxene, orthopyroxene, magnetite / titanomagnetite in microgranular porphyritic, hyalo-microlitic porphyritic and glomeroporphyritic matrix. Mineral chemistry data reveal that the pressure condition of the clinopyroxene crystallisation for the shoshonitic rocks are between 1.4 and 6.3 kbar corresponds to 6–18-km depth and the high-K calc-alkaline rocks are between 5 and 12 km. 40Ar/39Ar age data changing between 72 ± .5 Ma and 79.0 ± .3 Ma (Campanian) were determined for the Late Cretaceous Hamsilos volcanic rocks, contemporaneous with the subduction of the Neo-Tethyan Ocean beneath the Pontides. The studied volcanic rocks were enriched in the large-ion lithophile and light rare earth element contents, with pronounced depletion in the contents of high-field-strength elements. Chondrite-normalised rare earth element patterns (LaN/LuN = 6–17) show low to medium enrichment, indicating similar sources of the rock suite. Initial 87Sr/86Sr values vary between.70615 and.70796, whereas initial 143Nd/144Nd values change between.51228 and.51249. Initial 206Pb/204Pb values vary between 18.001 and 18.349, 207Pb/204Pb values between 15.611 and 15.629 and 208Pb/204Pb values between 37.839 and 38.427. The main solidification processes involved in the evolution of the volcanic rocks consist of fractional crystallisation, with minor amounts of crustal contamination ± magma mixing. According to geochemical evidence, the shoshonitic melts in the Hamsilos volcanic rocks were possibly derived from the low degree of partial melting of a subcontinental lithospheric mantle (SCLM), while the high-K calc-alkaline melts were derived from relatively high degree of partial melting of SCLM that was enriched by fluids and/or sediments from a subduction of oceanic crust.
- MakaleYalnız künye2016The investigation of adhesion and fatigue properties of TiN/TaN multilayer coatings
Baran, Ö.; Sukuroglu, E.E.; Efeoglu, İ.; Totik, Y.
TiN/TaN multilayer coatings exhibit excellent mechanical properties when compared to single layer nitride coatings. In this study, TiN/TaN multilayer coatings were deposited on Mo-alloy and W-alloy substrates by CFUBMS. The structural and mechanical properties of coatings were analysed using XRD, EDS, SEM and a micro-hardness tester, respectively. To determine the adhesion and fatigue behaviour of the coatings were performed a scratch test in two modes that a standard mode with progressive loading and sliding-fatigue multimode operation with unidirectional sliding, respectively. A microscope was used to characterize adhesion and fatigue failures. The structural, mechanical, adhesion and fatigue properties of TiN/TaN multilayer coatings significantly changed depending on the substrate.
- MakaleYalnız künye2016Lipstick politics and framing competition: an experiment about the Turkish Airlines news
Özarslan, Hüseyin; Güran, Mehmet Salih
ABSTRACT: Framing is a discourse forming procedure with a direct effect on the very meaning of the news coverage. While framing itself is unavoidable, its controlled usage requires not only individual journalistic awareness of cultural, social, ideological and even psychological factors, but it also requires an institutionalization and cultivation of journalistic best practice. This experiment studies the effects of different news framing practices of the same event on audience reception by using actual news coverage from the Turkish media. 348 students were randomly assigned to three experiment groups where they were exposed to actual news stories about a corporate attire regulation at the Turkish Airlines that had been recently issued. A factor analysis explored their thoughts on the news stories and produced respectively the managerial requirements frame and the repression of women frame as most apparent in the thoughts of the participants of the respective groups.
- MakaleYalnız künye2015A new species of the harvestmen genus Rilaena (Opiliones: Phalangiidae) from Turkey
Kurt, Kemal
A new harvestman species, Rilaena artvinensis sp. n. (Opiliones: Phalangiidae), is described and illustrated based on males collected in north-eastern Anatolia, Turkey. The new species is similar to R. buresi (Šilhavý, 1965) and R. lenkoranica Snegovaya, 2007. The differences between these species are elaborated.