Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2015Scopus SJRQ1Achieving room temperature superplasticity in Zn-5Al alloy at high strain rates by equal-channel angular extrusion
Demirtas, M.; Purcek, G.; Yanar, H.; Zhang, Z.J.; Zhang, Z.F.
Multi-pass equal-channel angular extrusion/pressing (ECAE/P) was applied to the eutectic Zn-5Al alloy to achieve high strain-rate (HSR) superplasticity in that alloy at room temperature (RT) by producing ultrafine-grained (UFG) microstructure. ECAE processing transformed the coarse-grained lamellar/spherical microstructure into a unique bimodal structure having equiaxed Zn-rich η-phase with a mean grain size of 540 nm and spherical Al-rich α-phase with an average grain size of 110 nm. The α-phase particles accumulated mainly along the η-phase boundaries. This unique microstructure brought about an extraordinary improvement in HSR superplasticity of the alloy even at RT. While the strength values decreased after ECAE, the elongation to failure increased substantially. The maximum elongation was 520% at the strain rate of 10-3 s-1, still high elongation of about 400% was achieved at a high strain rate of 10-2 s-1. This extraordinary improvement in HSR superplasticity of Zn-5Al alloy was attributed to the morphologically unique bimodal microstructure in UFG regime formed after ECAE. The grain boundary sliding (GBS) was found to be the main deformation mechanism for this alloy in superplastic regime.
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İncele - MakaleAçık Erişim2017Concept-teaching practices in social studies classrooms: Teacher support for enhancing the development of students’ vocabulary
İlter, İlhan
The purpose of this study is to describe social studies teachers’ perceptions related to their practices in teaching concepts within the context of social studies instruction in order to enhance students’ vocabulary development in their classes. The study focuses on how students’ breadth and depth of vocabulary knowledge is supported by teachers’ experiences and their self-reported practices in relation to teaching social studies content. The study has a qualitative research design and has been conducted with 35 middle-school social studies teachers selected in accordance with maximum variation sampling. A semi-structured interview form has been used to determine teachers’ perceptions and viewpoints, and data has been analyzed using content analysis techniques. Results show that the teachers’ espoused practices for enhancing social studies vocabulary and for assessing its overall development process supports widely accepted understanding and ideas on effective concept teaching and alternative assessment procedures. Some examples of these practices and assessment measures include interactive word-walls (ABC graffiti), contextualized vocabulary instruction, word analogy, semantic maps, vocabulary self-collection strategy, and concept circles. However, the majority of practices reported by the teachers reflect traditional tasks and methods that ignore how new concepts were acquired and also focus more on the definitional knowledge of words. Further research should include teacher observations along with interviews to validate actual classroom practices.
AtıfScopus3WoS3OpenAlex12İncele - MakaleYalnız künye2017Scopus SJRQ2Adsorptive properties of As(III) from aqueous solution using magnetic nickel ferrite (NiFe2O4) nanoparticles: Isotherm and kinetic studies
Karcioğlu Karakaş, Zeynep; Boncukcuoğlu, Recep; Karakaş, İbrahim Hakkı
As(III) adsorption on NiFe2O4 nanoparticles were systematically investigated by controlling parameters such as stirring rate, pH, initial arsenic concentration, contact duration, temperature, and adsorbent dose. It was observed that the amount of adsorbed arsenic concentration is strongly depended on pH and temperature. The temperature and pH give rise to significant changes in the amount of adsorbed arsenic. As compared with Langmuir and Freundlich isotherms models, the latter is found to be well suited. Pseudo-first order, pseudo-second order, and intraparticle diffusion models were applied to adsorption equilibrium data obtained from the analysis of arsenic with diverse amount of initial concentration.
AtıfScopus12WoS13OpenAlex11İncele - MakaleAçık Erişim2018Scopus SJRQ2Development of cloud point extraction preconcentration of cadmium and lead in solid samples using flame atomic absorption spectrometry
Bahadır, Zekeriyya; Yazar, Murat; Tümay, Süreyya Oğuz; Serencam, Hüseyin; Bektaş, Hakan; Duran, Celal
2-[(6-Morpholin-4-ylpyridin-3-yl)amino]-N’-(4-oxo-3-phenyl-1,3thiazolidin-2-ylidene) acetohydrazide (MPAPTAH) was first used in a cloud point extraction procedure to determine the cadmium and lead ions in solid samples. Triton X-114 was used as a mixed micellar medium. The optimal extraction parameters (e.g. surfactant concentrations, amount of ligand, pH etc.) were evaluated. The optimum experimental conditions for Cd and Pb ions during the extraction procedure were carried out with 0.7 mg of MPAPTAH agent, 1.0 mL 0.2% (w/v) of the surfactant, a pH of 8.0. Under the best analytical parameters, the detection limit (LOD) for Cd(II) and Pb(II) ions were found to be 0.6 μg L−1 and 1.91 μg L−1, while the relative standard deviation (RSD) was taken as 2.78 and 2.86%, respectively. Preconcentration factor (PE) of 50 was obtained from using 50 mL of the sample volume for both ions. The accuracy of the method was tested through analysis of Pb2+ and Cd2+ in certified reference material (CRM Sandy Soil C). The interference effect of certain cations and anions were also investigated. The recoveries of the analyte ions were almost quantitative in the presence of all the interfering ions. Afterwards, the developed method was successfully applied to find lead and cadmium in real solid samples, including black tea, tobacco, and chili pepper.
AtıfScopus9WoS8OpenAlex8İncele - BildiriAçık Erişim2016Scopus SJRQ4Thermodynamic analysis of a cascade refrigeration system
Karaali, R.
There is a need for cooling by using the waste heat energy in food industry. Absorption cycles can be driven by waste thermal, geothermal, solar or industrial processes energies. In this study, cascade refrigeration system is thermodynamically modeled, and analyzed by using first law of thermodynamics, and exergy method. Thermodynamic properties such as pressure, temperature, entropy, enthalpy, exergy, mass flow rate in each stream are calculated for 50, 75, 100?C and for 0.8, 1.0, and 1.5 MPa pump pressure. A computer program is used that was prepared in FORTRAN by the author for the analyses. It is found that the compression-absorption cascade cooling cycle is appropriate for most of the kind of waste heat applications. Increase of the generator inlet heat temperature increases the generator inlet heat, the absorber outlet heat and the condenser 2 outlet heat energies and decreases the coefficient of performance of the absorption and the overall cycles. The generator heat decreases with increase of the pump pressure. Also increase of the pump pressure decreases the coefficient of performance of the absorption and the overall cycles. Increase of the pump pressure and the generator temperature decreases the exergetic coefficient of performance. Increase of the generator temperature and pump pressure increases the generator inlet exergy. It is concluded that increase of the generator temperature and the pump pressure increases the total destructed exergy of the cycle.
AtıfScopus10WoS5OpenAlex13İncele - MakaleAçık Erişim2018Scopus SJRQ3Investigation of high-temperature-resistant rhenium–boron neutron shields by experimental studies and Monte Carlo simulations
Korkut, Turgay; Korkut, Hatun; Aygün, Bünyamin; Bayram, Özkan; Karabulut, Abdulhalik
In this study, novel rhenium–boron neutron-shielding high-temperature-resistant materials were designed. The considered samples, Re60–B40, Re58–B42, Re50–B50, and Re40–B60, with different concentrations of rhenium and boron were investigated to elucidate their neutron-shielding performances, and compare them with well-known neutron-shielding materials such as the 316LN quality nuclear steel. In addition to the experimental studies, Monte Carlo simulations were performed using the FLUKA and GEANT4 codes, where 4.5-MeV neutrons emitted by a 241Am–Be source were employed. Experimental equivalent dose rates, simulated track lengths, energy balances, and neutron mass absorption cross sections were discussed in detail.
AtıfScopus5WoS2OpenAlex4İncele - BildiriAçık Erişim2015Scopus SJRQ3Thermoeconomic analyses of steam injected gas turbine cogeneration cycles
Karaali, R.; Öztürk, I.T.
In this study, three different gas turbine cogeneration systems that are preheating air, preheating air-fuel and simple cycles where steam injected in to combustion chamber are analyzed. The effects of steam injection on thermoeconomic performance are calculated and obtained. By using the first law of thermodynamics, the exergy analysis and economic methods, simulation programs written by the authors in FORTRAN code are obtained to use for the analyses. Thermoeconomic performance of these three different cycles for different stage and variable mass of injected steam are obtained and compared with literature. The effects of injection steam in to combustion chambers of those three cycles for variable compressing ratios, on power, efficiencies, product price and performances are obtained. Consequently, the advantages and the disadvantages of injection steam are evaluated. The results obtained in this study are compared with the results available in the literature. Injection steam into combustion chamber increases the electricity efficiency and electricity power but decreases the heat power of the cycles. Also the produced electricity price for per kWh is increasing.
AtıfScopus15WoS12OpenAlex18İncele - MakaleAçık Erişim2019Scopus SJRQ2Investigation of structural, morphological and optical properties of Nickel-doped Zinc oxide thin films fabricated by co-sputtering
Bayram, Ozkan; Sener, Emre; İgman, Erdal; Simsek, Onder
In this study, it was aimed to grow Nickel doped (0.0 at.%, 0.16 at.%, 0.20 at. % and 0.24 at. %) Zinc Oxide (NZO) thin films on quartz substrates using Magnetron Sputtering technique. NZO thin films were obtained at a temperature of 450 °C, a pressure of 480 m Torr and a deposition time of 30 min. Co-sputtering process for both Ni and ZnO target was performed using two separate power sources. The DC power of the Ni target material was 20, 30 and 40 W, respectively while the radio frequency (RF) power of the Zinc oxide (ZnO) target material was set to 150 W. Using XRD analysis, thin films were found to have polycrystalline morphology, and the average crystallite size changed significantly depending on the increased Ni doping level. The optical Transmittance of the thin films was greater than 90% in the visible region (550 nm), and this value tends to decrease slightly by Ni doping. The optical band gap (E g ) firstly decreased and then slightly increased with the Nickel doping ratio and these values were found to be 3.23 eV, 3.11 eV and 3.15 eV, respectively, with increase of Ni doping.
AtıfScopus34WoS30OpenAlex37İncele - MakaleAçık Erişim2014Scopus SJRQ1Steady, dynamic and creep rheological analysis as a novel approach to detect honey adulteration by fructose and saccharose syrups: Correlations with HPLC-RID results
Yilmaz, Mustafa Tahsin; Tatlisu, Nevruz Berna; Toker, Omer Said; Karaman, Safa; Dertli, Enes; Sagdic, Osman; Arici, Muhammet
In this study, natural honey was adulterated with the addition of adulterants, namely saccharose and fructose syrups at a ratio of 0%, 10%, 20%, 30%, 40% and 50% by weight. Steady, dynamic and creep tests were conducted, revealing that the changes in the flow, viscoelastic and creep behavior of natural honey were clear and remarkable. Syrup addition decreased viscosity (η), storage (G') and loss modulus (G″) values of the control honey samples. Deformation represented by the compliance (J(t)) values was more prominent in the adulterated honey samples. In addition, HPLC-RID analysis was conducted to determine major sugar composition of the adulterated samples. Pearson's correlation test indicated that there were significant (P<0.05; 0.01) correlations between sugar composition and rheology parameters, η (viscosity), K″, K* (intercepts for G″ and complex modulus (G*), respectively) and η0 (viscosity of Maxwell dashpot), suggesting that K', K″, K* and η0 could be prominent indicators for presence of saccharose or fructose syrups added in natural honey within the studied concentration levels. These results suggested that use of steady, dynamic and creep analysis would be a novel and potential approach to detect honey adulteration by fructose and saccharose syrups.
AtıfScopus81WoS72OpenAlex80
İncele - MakaleAçık Erişim2019Scopus SJRQ3Whole cell application of Lactobacillus paracasei BD101 to produce enantiomerically pure (S)-cyclohexyl(phenyl)methanol
Şahin, Engin; Serencam, Hüseyin; Dertli, Enes
In this study, a total of 10 bacterial strains were screened for their ability to reduce cyclohexyl(phenyl)methanone 1 to its corresponding alcohol. Among these strains, Lactobacillus paracasei BD101 was found to be the most successful biocatalyst to reduce the ketones to the corresponding alcohols. The reaction conditions were systematically optimized for the reducing agent L paracasei BD101, which showed high enantioselectivity and conversion for the bioreduction. The preparative scale asymmetric reduction of cyclohexyl(phenyl)methanone (1) by L paracasei BD101 gave (S)-cyclohexyl(phenyl)methanol (2) with 92% yield and >99% enantiomeric excess. The preparative scale study was carried out, and a total of 5.602 g of (S)-cyclohexyl(phenyl)methanol in high enantiomerically pure form (>99% enantiomeric excess) was produced. L paracasei BD101 has been shown to be an important biocatalyst in asymmetric reduction of bulky substrates. This study demonstrates the first example of the effective synthesis of (S)-cyclohexyl(phenyl)methanol by the L paracasei BD101 as a biocatalyst in preparative scale.
AtıfScopus39WoS37İncele - MakaleYalnız künye2016Scopus SJRQ1Antibacterial poly(lactic acid) (PLA) films grafted with electrospun PLA/allyl isothiocyanate fibers for food packaging
Kara, Hasan H.; Xiao, Fugang; Sarker, Majher; Jin, Tony Z.; Sousa, Ana M. M.; Liu, Cheng-Kung; Tomasula, Peggy M.; Liu, Linshu
Poly(lactic acid) (PLA) fibers of submicron sizes encapsulating allyl isothiocyanate (AITC) (PfA) were made and electrospun onto the surfaces of PLA films. SEM examination confirmed the fusion of the two phases to form a bilayered fiber-grafted film after the film underwent air blowing and water washing to remove the nongrafted fibers. The fiber-grafted PLA films (PfA-g-film) retain the mechanical properties of PLA. The release of AITC from the fibers was temperature dependent. At temperatures lower than 4°C, the incorporated AITC remained within the fibers without losing activity; at room temperature, AITC released in a sustained manner over weeks. The release of AITC was also dependent on its initial concentration in the PLA electrospinning solution; samples with more AITC incorporated showed a higher release rate. PfA-g-films significantly inhibited the growth of Listeria innocua and Escherichia coli k12 when tested on package foods.
AtıfScopus48WoS36OpenAlex50İncele - MakaleAçık Erişim2016Scopus SJRQ1Effect of different processes on lamellar-free ultrafine grain formation, room temperature superplasticity and fracture mode of Zn-22Al alloy
Demirtas, M.; Purcek, G.; Yanar, H.; Zhang, Z.J.; Zhang, Z.F.
The Zn-22 wt.%Al was processed using five different selected routes including thermal, thermo-mechanical and severe plastic deformation (SPD) techniques in order to produce ultrafine grained (UFG) microstructure for achieving room temperature (RT) and high strain rate (HSR) superplasticity, and to compare the same set of the results. After all routes, the microstructural evolutions and RT uniaxial tensile tests at different strain rates ranging from 1 × 10-3 to 1 × 100 s-1 were investigated. The smallest grain size was achieved to be 300 nm after the thermo-mechanical process including conventional hot and cold rolling steps. However, the lamellar microstructure of the alloy was not completely eliminated during that process. On the other hand, equal-channel angular pressing (ECAP) as one of the SPD techniques decreased the grain size down to 400 nm with a lamellar-free microstructure. The maximum elongation value was achieved to be 330% with the sample tested at 1 × 10-3 s-1 after a thermo-mechanical process including conventional hot and cold rolling, and an aging stage between these rolling steps. It was found that lamellar-free microstructure causes higher superplastic elongation even if it has higher grain size compared to the sample having partially lamellar structure.
AtıfScopus40WoS39İncele - MakaleAçık Erişim2016Scopus SJRQ3Investigation of the cyanide leaching optimization for ultrafine grinding gold–silver ore
Birol, Onur; Uçurum, Metin
In recent years, the ultrafine grinding (UFG) process has become increasingly important for the recovery of precious metals (especially for Au and Ag) from raw ores. It is well known that cyanide leaching of gold–silver ore has been an accepted process in the world. In the current study, UFG was proposed as a pretreatment method prior to cyanide leaching of a gold–silver ore. First, the ore was crushed and ground by jaw, cone crusher, and ring mill, respectively. Particle size of ground product was 75 µm based d80. Second, the fine product was subjected to the grinding process by vertical wet stirred ball mill, and the final ultrafine product was used as leach feed material. The leach feed material had about d80 = 20 µm and d50 = 6.02 µm particle size. Some important leaching parameters were optimized by using the ultrafine powder in the study. The final leach experiments demonstrated that the recoveries of Au and Ag were 91.92% and 82.15% under optimum leaching conditions such as 150 kg/t quicklime dosage, 25% pulp density, 85°C leach temperature, 500 g/t cyanide concentration, and 90 h leaching time.
AtıfScopus11WoS10OpenAlex11İncele - BildiriAçık Erişim2015Scopus SJRQ3Soil stabilization with using waste materials against freezing thawing effect
Yilmaz, F.; Kamiloʇlu, H.A.; Şadoʇlu, E.
Freezing-thawing processes hapenning in seasonally cold climate cause deformation of soil in time of freezing and strength loss while thawing. Problems of ground frost heave and soil softening belong to the important factors, that could cause serious damage and financial loss. Bayburt tuff and tuffites known as Bayburt Stone mines, located around Bayburt, play important role on economy of the Bayburt city. As a result of researches in 2005 total of 2 535 700 tons proved reserve were determined several places in Bayburt. The goal of this study is proving, that deposits of Green Bayburt Stone wastes, created in the stone quarries during the stone processing, can be used as a stabilizing material. By recycling the waste material rejected stone was mixed with lime and used as a soil stabilizator against freezing-thawing effect. Prepared natural and stabilized soil samples were subjected to freezing-thawing cycles after curing for 28 days. After the freezing-thawing cycles, compressive strength of the samples was measured to investigate the influence of the additives on the freezing-thawing properties of soil samples. As a result of this study, it was determined that samples stabilized with Green Bayburt Stone mixtures have high freezing-thawing durability as compared to unstabilized samples. As a consequence, it was seen that those mixtures can be successfully used as an additive material to enhance the freezing-thawing effects of cohessive soils.
AtıfScopus25WoS23OpenAlex28İncele - MakaleYalnız künye2018Scopus SJRQ2Levitation and guidance force relaxations of the single−seeded and multi−seeded YBCO superconductors
Abdioglu, M.; Ozturk, K.; Kabaer, M.; Ekici, M.
The stable levitation and guidance forces at higher force levels are important parameters for technological applicability of high temperature superconductors (HTSs) in Maglev and Flywheel energy storage systems. In this study, we have investigated the levitation and guidance force relaxation of both the single-seeded and multi-seeded YBCOs for different (HTS)−permanent magnetic guideway (PMG) arrangements in different cooling heights (CH). The measured saturated force values of Halbach PMG arrangements are bigger than the maximum force values of other PMGs. It is determined that the normalized magnetic levitation force (MLF) and normalized guidance force (GF) relaxation rate values decrease while the relaxation rates increase with increasing magnetic pole number and the effective external magnetic field area for both the single−seeded and multi−seeded YBCO. Also it can be said that the force stability at the higher force value of Halbach PMG arrangement indicates that the relaxation quality of Halbach PMG is better than that of the others. Additionally, it can be said that both the MLF and GF relaxation qualities of the multi−seeded YBCOs are better than that of the single−seeded ones. This magnetic force and relaxation results of the single−seeded and multi−seeded YBCOs are useful to optimize the loading capacity and lateral reliability of HTS Maglev and similar magnetic bearing systems.
AtıfScopus5WoS5OpenAlex6İncele - MakaleAçık Erişim2018Scopus SJRQ2Effect of the number of cycles on the optical and structural properties of Mn3O4 nanostructures obtained by SILAR technique
Bayram, Ozkan; Simsek, Onder; Guney, Harun; Igman, Erdal; Murat Ozer, Mustafa
In this study, nanostructured Mn3O4 (manganese oxide) thin films were successfully obtained by successive ionic layer adsorption and reaction (SILAR) method on the soda lime glass substrates using Manganese Nitrate (Mn(NO3)2) and Ammonium hydroxide (NH4(OH)) as cationic and anionic precursors respectively. Structural and morphological characterizations of the Mn3O4 films obtained at different cycles were determined using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The crystal structure of the thin films were also confirmed by RAMAN spectroscopy. Optical properties such as absorption, transmission, reflection, extinction coefficient and optical band gap of nanostructured Mn3O4 thin films were determined by UV–Vis spectroscopy. SEM images showed that the manganese oxide nanosheets formed uniformly on substrate surface. As the deposition cycles increased, nano-sheets structure deteriorated. The optical band gap of Mn3O4 thin films varied from 2.12 to 2.59 eV, depending on the increase in number of cycles. From contact angle measurements of thin films, it was determined that thin films had hydrophilic character.
AtıfScopus14WoS14OpenAlex16İncele - MakaleAçık Erişim2015Scopus SJRQ1Using solar greenhouses in cold climates and evaluating optimum type according to sizing, position and location: A case study
Çakir, Uğur; Şahin, Erol
This study deals with a comparison among five common greenhouse types with regard to total solar radiation gaining rates in greenhouse using season under some assumptions. Additionally, possibility of using greenhouses in cold climate regions is investigated. We analyzed five greenhouse types and developed a script in MATLAB platform for the solar radiation availability. This model is applicable and suitable for other buildings and places on the world. Even-span, uneven-span, vinery, semicircular and elliptic types of greenhouses have been analyzed. A "k" value (ratio of length to width of greenhouse) and greenhouse azimuth angle (GAA) are described. Seven different floor area are assigned for each greenhouse type such as 50m2, 100m2, 150m2, 200m2, 250m2, 300m2 and 400m2, respectively. For each floor area, k value is assigned from 1 to 10. Each greenhouse is oriented in 90 different angles according to south facade. Seasonal total solar energy gaining rates is computed individually for all possible greenhouse types, area, k number and orientation. Then a comprehensive comparison is made to determine the optimal greenhouse. The results show that greenhouses are usable and suitable for using in cold climate regions to increase the productivity. In addition, the elliptic type is the optimum one in all analyzed types of greenhouses for Bayburt conditions for all floor areas. It is followed by uneven-span, even-span, semi-circular and vinery type of greenhouses respectively. Shape and type of the roof are main effective parameters on solar energy gaining rates of greenhouses. Elliptic greenhouse should be preferred on the band of the latitude of Bayburt, unless there is restrictive factor like sizing and terrain.
AtıfScopus93WoS77OpenAlex95İncele - MakaleYalnız künye2018Scopus SJRQ1Thermoeconomic analysis and optimization of a Re-compression supercritical CO2 cycle using waste heat of Gaziantep Municipal Solid Waste Power Plant
Tozlu, Alperen; Abuşoğlu, Ayşegül; Özahi, Emrah
This paper presents thermodynamic and thermoeconomic analyses as well as optimization of a re-compression supercritical CO2 cycle. A gas turbine cycle (GT) is adapted as a model to an existing plant to generate additional power in Gaziantep Municipal Solid Waste Power Plant (GMSWPP). The total capital cost rate and total cost rate of the GT cycle are found to be 20.47 $/h and 77.14 $/h, respectively utilizing SPECO by using the exhaust gas of 16 kg/s with 1.9 bar and 566.7 °c. The net power, the energy and exergy efficiencies, the total cost and the total capital cost rates of the GT cycle are optimized by +1.73%, +3.21%, +2.45%, −1.11% and −1.64%, respectively using NSGA-II in MATLAB in the range of 2.5≤PR≤4, 200≤P6≤216, 16≤T0≤23 and 9.1≤LMTD≤12.9. This paper provides an originality such that optimization as well as thermodynamic and thermoeconomic analyses is performed simultaneously for an existing MSW power plant, which can be stressed that there are scarce amounts of studies related on this field. Moreover, as another novelty, it can be emphasized that net power output of such like plants which have similar capacity can be improved using the developed model and NSGA-II optimization method.
AtıfScopus47WoS43OpenAlex48İncele - MakaleAçık Erişim2015Scopus SJRQ2Deposition of a Mo doped GaN thin film on glass substrate by thermionic vacuum arc (TVA)
Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan
Current research presents a new deposition method for GaN thin films that produces in a very short production time for GaN-based solid-state applications. A Mo doped GaN thin film on a glass substrate was produced by thermionic vacuum arc (TVA) technique. The TVA technique is a novel non-reactive plasma technique. The optical properties were determined by Filmetrics F20 interferometer and UV–Vis double beam spectrophotometer. The surface morphology was analyzed using field emission scanning electron microscopy and atomic force microscopy. The mean thickness value was measured as 100 nm by Filmetrics interferometer. The crystalline structure of the produced thin film has a Wurtzite crystal structure (004) as obtained by X-ray diffraction. Hardness value was determined as 14 GPa with the Oliver–Pharr method. The obtained properties are consistent with the values reported in related literature. The findings indicate that the TVA method provides advantages for optical and industrial applications.
AtıfScopus20WoS20OpenAlex22İncele - 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
