Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Pat, Suat(8)
- Özen, Soner(8)
- Agar, Guleray(6)
- Akkus, B.(6)
- Kizil, Hamit Emre(6)
- Ozdamli, F(6)
- Uzunboylu, H(6)
- Akdemir, A.O.(5)
- Ayberkin, Doruk(5)
- Dadasoglu, F.(5)
- Dertli, Enes(5)
- Dogan, G.S.(5)
- Ekinci, A.(5)
- Han, I.(5)
- Kanbul, S(5)
- Karagoz, K.(5)
- Karahoca, A(5)
- Korkmaz, Şadan(5)
- Oktem, Y.(5)
- Oztekin, A.(5)
- Set, E.(5)
- Tabakcioglu, Mehmet Baris(5)
- Şenay, Volkan(5)
- Akcamete, G(4)
- Anar, Mustafa(4)
- Babadoan, C(4)
- Chova, LG(4)
- Kaban, Guzin(4)
- Kahraman, Sakip(4)
- Karaali, R.(4)
- Kaya, Mukerrem(4)
- Martinez, AL(4)
- Mutlu, R.B.C.(4)
- Oulmu, S(4)
- Torres, IC(4)
- Yalcin, L.S.(4)
- Allm, Bünyamin(3)
- Caliskan, H(3)
- Guler, Evrim(3)
- Gürses, Ahmet(3)
Yayınlar
- BildiriAçık Erişim2018Scopus SJRQ3Room temperature superplasticity in fine/ultrafine-grained Zn-Al alloys with different phase compositions
Demirtas, Muhammet; Yanar, Harun; Saray, Onur; Purcek, Gencaga; Kaibyshev, R.; Tikhonova, M.; Itoh, G.; Taleff, E.M.; Sato, E.
Three Zn-Al alloys, namely Zn-22Al, Zn-5Al and Zn-0.3Al, were subjected to equal-channel angular pressing (ECAP), and the effect of ECAP on their microstructure and room temperature (RT) superplastic behavior were investigated in detail referring to previous studies reported by the authors of the current study. ECAP remarkably refined the microstructures of three alloys as compared to their pre-processed conditions. While the lowest grain size was achieved in Zn-22Al alloy as 200 nm, the grain sizes of Zn-5Al and Zn-0.3Al alloys were ~540 nm and 2 µm, respectively, after ECAP. After the formation of fine/ultrafine-grained (F/UFG) microstructures, all Zn-Al alloys exhibited superplastic behavior at RT and high strain rates. The maximum superplastic elongations were 400%, 520% and 1000% for Zn-22Al, Zn-5Al and Zn-0.3Al alloys, respectively. It is interesting to point out that the highest RT superplastic elongation was obtained in Zn-0.3Al alloy with the largest grain size, while Zn-22Al alloy having the lowest grain size showed the minimum superplastic elongation. This paradox was attributed to the different phase compositions of these alloys. The formation of Al-rich α/α phase boundaries, where grain boundary sliding is minimum comparing to Zn-rich η/η and η/α phase boundaries of Zn-Al alloys, is the lowest level in Zn-0.3Al alloy among all the alloys. Therefore, it can be concluded that if it is desired to achieve high superplastic elongation in Zn-Al alloys at RT, keeping Al content at a possibly minimum level seems to be the most suitable way.
AtıfScopus6OpenAlex5
İncele - BildiriAçık Erişim2017Learners' views about cloud computing-based group activities
Yildirim, Serkan; Bölen, Mehmet Cem; Yildirim, Gurkan; Masal, E; Onder, I; Besoluk, S; Caliskan, H; Demirhan, E
Thanks to its use independently of time and place during the process of software development and by making it easier to access to information with mobile technologies, cloud based environments attracted the attention of education world and this technology started to be used in various activities. In this study, for programming education, the effects of extracurricular group assignments in cloud based environments on learners were evaluated in terms of group work satisfaction, ease of use and user satisfaction. Within the scope of computer programming education lasting eight weeks, a total of 100 students participated in the study including 34 men and 66 women. Participants were divided into groups of at least three people considering the advantages of cooperative learning in programming education. In this study carried out in both conventional and cloud based environments, between groups factorial design was used as research design. The data collected by questionnaires of opinions of group work were examined with quantitative analysis method. According to the study results extracurricular learning activities as group activity created satisfaction. However, perceptions of easy use of the environment and user satisfaction were partly positive. Despite the similar understandings; male participants were easier to perceive use of cloud computing based environments. Some variables such as class level, satisfaction, computer and internet usage time do not have any effect on satisfaction and perceptions of ease of use. Evening class students stated that they found it easy to use cloud based learning environments and became more satisfied with using these environments besides being happier with group work than daytime students.
AtıfOpenAlex3
İncele - BildiriAçık Erişim2017Scopus SJRQ1Antiproliferative and apoptotic properties of vulpinic acid on A549, AGS and HeLa cells
Kizil, Hamit Emre; Agar, Guleray
- BildiriYalnız künye2017Harvesting Solar Energy for Limited-Energy Problem in Wireless Sensor Networks
Kosunalp, Selahattin; Cihan, Ahmet
The major problem in wireless sensor networks (WSNs) is the limited-energy source, typically small batteries, employed by sensors. In order to prolong the lifetime of the WSNs, a lot of approaches have taken the limited-energy problem as a primarily design criterion. However, inevitable energy depletion will eventually disturb the operation of the WSNs. Recent studies have shown that renewable energy sources would potentially provide an infinite energy source for powering WSNs. Solar energy is the most effective energy source for WSNs as it has the largest power intensity. Therefore, each sensor which requires a small amount of energy for efficient operation can harvest sufficient energy from solar. In this study, a platform is designed in order to allow sensors to exploit solar energy. The performance of the sensors in terms of the lifetime is practically studied. The results demonstrate that sensors can also survive when there is no energy available through storing energy in a super-capacitor. IRIS nodes are used in experiments as they are very popular in WSNs domain.
- BildiriAçık Erişim2017Scopus SJRQ1Determination of the Antigenotoxic effects of Evernic acid against genotoxic effects of CCL4 on HUVEC lines
Agar, Guleray; Kizil, Hamit Emre; Ceker, Selcuk; Capik, Ozel; Sengul, Bulent
- BildiriAçık Erişim2017Scopus SJRQ1Nanoemulsion-based delivery systems to improve functionality of oregano essential oil: Molecular characterization and in vitro antifungal activity
Ermis, Ertan; Cicek, Perihan Kubra; Meral, Raciye; Yilmaz, Azime; Dertli, Enes; Yilmaz, Mustafa Tahsin
AtıfWoS1OpenAlex1İncele - BildiriYalnız künye2017Multi-manned assembly line balancing problem: Resource constrained case
Yilmaz, Hamid; Yilmaz, Mustafa
In this paper, a new approach on multi-manned assembly line balancing problem is presented. The goal of proposed approach is to establish balance of multi-manned assembly line with minimum number of worker, workstation and resources. For this purpose, mathematical model is developed for the problem. Finally, this model is solved for a numerical example using Gurobi to indicate the applicability of the proposed mathematical model.
AtıfScopus1İncele - BildiriAçık Erişim2017Optimization of RT superplasticity of UFG Zn-22Al alloy by applying ECAP at different temperatures and phase regions
Demirtas, M.; Yanar, H.; Purcek, G.; Estrin, Y.; Liao, X.
Zn-22Al alloy was subjected to either one-step or two-step equal channel pressing (ECAP) to investigate the effect of processing temperature on its microstructure and room temperature (RT) superplasticity. In one-step ECAP processes, 4 passes ECAP were applied to the alloy at different temperatures: RT, 100°C and 250°C in two-phase region below eutectoid temperature and 350°C in single-phase region above eutectoid temperature. In two-step ECAP processes, one-step ECAP-processed samples were subjected to four more passes ECAP at RT. Considering the one-step ECAP processing, RT superplasticity increased with decreasing ECAP temperature as expected, and the highest RT superplasticity was achieved as 350% after 4 passes ECAP at RT. On the other hand, application of 4 more passes ECAP at RT to the sample showing the lowest superplastic elongation after one-step ECAP (the sample processed at 350°C) resulted in the maximum RT elongation of 400% at a high strain rate of 5×10-2 s-1. These results suggest that first step temperature of two-step ECAP process is needed to increase above the eutectoid point of Zn-22Al alloy to achieve high RT superplasticity. These results were attributed to the changes in microstructure inside the single-phase and two-phase regions during the processes.
AtıfScopus12WoS10OpenAlex9İncele - BildiriYalnız künye2017Influence of ball and powder filling ratios (Jb and fc) on the dry grinding process of calcite
Uçurum, M.; Bayraktar, I.; Ozyurt, M.; Atalay, F.; Torun Bilgic, E.; Karadeniz, M.; Gulsun Kilic, M.; Onel, O.
Turkey has important quantity of industrial minerals and calcite is one of them and is used as filler in the industries such as plastics, rubber, and paint, to gain a variety of features to products. In order to use calcite as filler, some specific properties such as fine product size are required. In the world, conventional ball mill technology is used to obtain calcite with micronized on the industrial scale. In the mill, ball filling ratio (Jb) and powder filling ratio (fc) directly affect product size, energy consumption, and grinding costs. In this study, influence of important operating parameters such as ball and calcite filling ratios (Jb and fc) on the grindability of calcite ore was examined to obtain a fine product (<100 μm) in the conventional ball mill. The batch test results show that the parameters play an important role in the fine grinding process of calcite.
- BildiriAçık Erişim2017Scopus SJRQ3Evaluation of marble dust for soil stabilization
Yilmaz, F.; Yurdakul, M.
Usage of marble dust was investigated for soil stabilization in the scope of utilization of waste material. Geotechnical properties, such as compaction, Atterberg limits, unconfined compressive strength of the mixtures and changes of these properties with the marble dust ratio were determined. From the test results it is seen that marble dust increases the mechanical properties of soil and application of dust wastes for soil stabilization will be an efficient practice in terms of solid waste management.
AtıfScopus20WoS11OpenAlex23İncele - BildiriYalnız künye2017Effect of chemical dosage on color parameters of hydrophobic calcium carbonate obtained in aqueous solution
Uçurum, M.; Bayraktar, I.; Ozyurt, M.; Atalay, F.; Torun Bilgic, E.; Karadeniz, M.; Gulsun Kilic, M.; Onel, O.
Ultra-fine ground calcium carbonate is widely utilized as a performance mineral in rubber, plastics and paper industries. Both micronized calcium carbonate and a chemical (sodium oleate) treated calcium carbonate products, obtained in the aqueous solution, were used in the experiments. The color property is an important factor that affects the acceptability of the industrial mineral products. The current study describes the relationship between micronized calcium carbonate and coated calcium carbonate on the basis color parameters (L∗, a∗, b∗), whiteness index (WI), saturation index (SI), hue angle (H) and total color difference (ΔE). The results showed that the processing variables (chemical dosage) did not have a significant effect on the color parameters of hydrophobic calcium carbonate products.
- BildiriYalnız künye2017Examination of absorption effects at the Compton to coherent scattering intensities X-rays using Fe-Ca and Fe-Ti binary compounds with WDXRF
Boydaş, Elif; Boydaş, Mustafa Gökalp; Allm, Bünyamin; Akdemir, A.O.; Ekinci, A.; Han, I.; Oztekin, A.; Set, E.; Dadasoglu, F.; Karagoz, K.
Matrix absorption effects have been examined with scattered X-rays by using WDXRF system for Fe-Ca and Fe-Ti binary compounds. Fe as analyte and elements which some of them the K absorption edge just below the characteristic K X-ray energies of the analyte (Fe) as matrix have been chosen. Pure and binary with Fe ratio ranging from 10% to 90% samples were prepared with these elements. These samples have been analyzed in WDXRF system. At the end of measurement, the coherent and Compton scattering X-rays data of Rh Kα X-rays from these samples have been obtained. Matrix absorption effects have been examined by calculating coherent / Compton scattered X-rays intensity ratio.
AtıfScopus3WoS2OpenAlex2İncele - BildiriYayıncıda açık erişim2017Thermal and Acoustic Properties of Aerogels: Preliminary Investigation of the Influence of Granule Size
Moretti, Elisa; Merli, Francesca; Cuce, Erdem; Buratti, Cinzia; Capozzoli, A.; Serra, V.; Howlett, R.
The influence of granules size in silica aerogels is experimentally investigated in terms of thermal and acoustic performance characteristics. The transmission loss (TL) is measured at normal incidence in a traditional impedance tube, whereas the thermal conductivity (λ) is evaluated using a Hot Plate apparatus, setting up an appropriate methodology, due to the nature of the sample. The results reveal that the small granules (granules size in the 0.01-1.2 mm range), which have the highest density, have the best performance both in terms of thermal and acoustic properties. Depending on the granules size, λ varies in 19-22 mW/mK range at 10°C, whereas a TL equal to 13 dB at about 6400 Hz for 20 mm thickness is obtained for small granules.
AtıfScopus58WoS46OpenAlex63İncele - BildiriAçık Erişim2017Scopus SJRQ3Effect of copper addition to aluminium alloys on surface roughness in terms of turning operation
Özen, F.; Fiçici, F.; Dündar, M.; Çolak, M.
Aluminium alloys have found usage in numerous industries due to some superior properties, such as high strength-to-weight ratios and high oxidation resistance. Aluminum alloys can be strengthened by some techniques. One of them, the most practical one, is precipitation hardening in aluminum alloys. By adding Cu, aluminum gains strength and hardness. In this work the machinability of unalloyed aluminum and aluminum alloyed with 4% and 8% of Cu have been investigated. Machinability assessment was executed in terms of surface roughness during turning operation. Specimens were manufactured by sand casting method, which is a commonly utilized casting operation. In machinability experiments, three different cutting tool materials were employed. Three different cutting speeds and three different feed rates have been used. Effect of these feeds, speeds and cutting tool materials on surface roughness has been studied. In addition, effect of Cu addition to aluminum alloys on surface roughness has been examined.
AtıfScopus9WoS6OpenAlex10İncele - BildiriYalnız künye2017Analysis of turbulent convective heat transfer from rectangular baffles by Taguchi method
Sahin, B.; Bayrakceken, A.; Manay, E.; Ates, I.
In this study, the effects of the rectangular baffles mounted on the bottom surface of a heat exchanger on the heat and pressure drop characteristics were investigated using the Taguchi experimental-design method. Nusselt number and friction factor were considered as performance parameters. An L18(2135) orthogonal array was selected as an experimental plan for the six parameters: corner angle (α), inclination angle (β), baffle height (H), baffle length (L), baffle width (S) and Reynolds number. First of all, each goal was optimized, separately. Then, all the goals were optimized together, considering the priority of the goals. The presence of the rectangular cross sectioned baffles caused higher pressure drop than that of the smooth channel. It was concluded that increasing inclination angle and corner angle caused heat transfer to decrease. The length of the baffle was found to be the most influential parameter on friction factor. Likewise, it was concluded that the most affected parameter on the heat transfer was Reynolds number.
- BildiriAçık Erişim2017Scopus SJRQ3Thermodynamic performance assessment of different fluids in a typical organic Rankine cycle for usage in municipal solid waste power plant
Özahi, E.; Tozlu, A.; Abuşoǧlu, A.
This paper presents the energy and exergy analyses of some different organic fluids which can be used in an organic Rankine cycle adapted to a municipal solid waste power plant in the frame of energy recovery. The novelty of the study is to adapt a well-known organic Rankine cycle system theoretically to the existing municipal solid waste power plant where the exhaust gas with a temperature of almost 560 °C is sent to atmosphere causing both energy loss and air pollution, and also violating the related legislation. The efficient organic fluid that can be used in such a plant is estimated by means of the thermodynamic analyses. It is known that, in a typical municipal solid waste power plant, a considerable amount of energy is sent up from a plant chimney to the atmosphere. This waste energy can be utilized by using an adapted organic Rankine cycle system with a proper organic fluid. In this frame, some different organic fluids were examined and compared thermodynamically in this study. The optimal operation conditions of some organic fluids, R141b, isobutane, R245fa, n-pentane and n-hexane have been evaluated by means of ASPEN and EES software programs. The effects of the outlet temperature of heat source on the energetic and exergetic efficiencies and the net power output at a given pinch point temperature difference were investigated. It can be deduced from the analyses that n-hexane has the highest energetic and exergetic efficiencies at all outlet temperatures of the heat source such as 8.92% and 34.47% at 82.08°C, respectively. It can also be stated that the maximum net power output is obtained by using the organic fluid n-hexane.
AtıfScopus14WoS12OpenAlex13İncele - BildiriAçık Erişim2017Scopus SJRQ3Thermoeconomic analysis and assessment of Gaziantep municipal solid waste power plant
Tozlu, A.; Abuşoǧlu, A.; Özahi, E.
This paper presents a thermoeconomic analysis and assessment of a municipal solid waste power plant system in Gaziantep. The operation of an existing municipal solid waste power plant is described in detail and a thermoeconomical methodology based on exergoeconomic relations and specific exergy costing (SPECO) method is provided to allocate cost flows through subcomponents of the plant. SPECO method is based on a step by step procedure which begins from identification of energy and exergy values of all states defined in the present system through fuel (F) and product (P) approach and ends at the point of establishing related exergy based cost balance equations together with auxiliary equations. The actual exergy efficiency of the solid waste power plant is determined to be 47.84% which shows that 52.16% of the total exergy input to the plant is destroyed. The net electrical power output of the Gaziantep municipal solid waste power plant is 5.655 MW. The total cost rate of the power plant is evaluated as 18.44$/h as a result of thermoeconomic analyses.
AtıfScopus12WoS13OpenAlex16İncele - BildiriAçık Erişim2017Relations of attention and meditation level with learning in engineering education
Ülker, Büsra; Tabakcioǧlu, Mehmet Bariş; Çizmeci, Hüseyin; Ayberkin, Doruk
Neurons use electricity in order to communicate to each other. Due to numerous signals sent by neurons, there are oodles of electrical activity in the brain. Sensitive equipment like electroencephalogram (EEG) biosensor perceives the brainwaves emanated from neurons. Beta waves are responsible for problem solving or decision making and associated with attention. Alpha waves are associated with now and meditation. Neurosky EEG biosensor perceives the brainwaves and transforms these brainwaves into attention and meditation values. In this study, Neurosky EEG biosensor is used for measuring the attention and meditation levels of students. A program is developed in C# medium. The developed program records raw brainwave data, attention and meditation average while the students are studying. As the attention and meditation levels are high, the students learn the subjects in the course. If predetermined meditation and attention level are not caught, the developed program does not give permission to pass to another subject. Because of that the students have less meditation and attention average than the predetermined value; they get fewer grades in the exam.
AtıfScopus16OpenAlex16İncele - BildiriAçık Erişim2017Determination of K shell XRF parameters and K to L shell vacancy transfer probabilities of ferromagnetic 3d transition metals
Allm, Bünyamin; Uǧurlu, Mine; Han, Ibrahim; Demir, Lütfü; Akdemir, A.O.; Ekinci, A.; Han, I.; Oztekin, A.; Set, E.; Dadasoglu, F.
In this study, K shell X-ray fluorescence cross-sections (σKα, σKβ and σK), K shell fluorescence yields (ωK) and K to L shell vacancy transfer probabilities (ηKL) of ferromagnetic 3d transition metals (Fe, Co, Ni) were investigated to understand how the relationship between ferromagnetism and these values changes with atomic number by using energy dispersive X-ray fluorescence (EDXRF) technique. The all obtained experimental and theoretical results were comparatively given as a function of the atomic number. It was clearly observed that all of the investigated parameters depend on the atomic number and the ferromagnetism state of the atom.
AtıfScopus3WoS2OpenAlex5İncele - BildiriAçık Erişim2017The speed control of DC motor under the load condition using PI and PID controllers
Corapsiz, Muhammed Reşit; Kahveci, Hakan; Akdemir, A.O.; Ekinci, A.; Han, I.; Oztekin, A.; Set, E.; Dadasoglu, F.; Karagoz, K.
In this study, it was aimed to compare PI (Proportional-Integral) and PID (Proportional-Integral-Derivative) controllers for speed control of Permanent Magnet Direct Current (PMDC) motor under both load and without load. For this purpose, firstly, the mathematical model was obtained from the dynamic equations of the PMDC motor and the obtained mathematical model was transferred to the simulation environment and modeled using Matlab/SIMULINK. Following the modeling process, PI and PID controller structures were formed, respectively. Secondly, after these structures were formed, the PMDC motor was run without any controller. Then, the control of the PMDC motor with no load was provided by using PI and PID controllers. Finally, the PMDC motor were loaded under the constant load (TL = 3 N.m.) for each condition and selected time period (t = 3 s). The obtained result for each control operations was comparatively given by observing effects of loading process on systems. When the obtained results were evaluated for each condition, it was observed that PID controller have the best performance with respect to PI controller.
AtıfScopus3OpenAlex4İncele