Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(62)
- Merdan, Mehmet(58)
- Duran, Celal(50)
- Ozdes, Duygu(47)
- Kaygusuz, Abdullah(43)
- Ashyralyyev, Charyyar(38)
- Karsli, Orhan(33)
- Öztürk, Serkan(32)
- Araz, Onur(31)
- Demir, Selim(29)
- Kulakaç, Nurşen(29)
- Dokuz, Abdurrahman(28)
- Arslan, Mehmet(27)
- Baltacı, Cemalettin(27)
- Maden, Nafiz(27)
- Sipahi, Ferkan(27)
- Topal, Fevzi(27)
- Turan, Ibrahim(27)
- Kandemir, Raif(25)
- Kurt, Kemal(24)
- Ozturk, Samet(24)
- Peker, Iskender(24)
- Vural, Alaaddin(24)
- Reis, Hatice Catal(23)
- Yücel, Cem(23)
- Aydin, Faruk(22)
- Baltaci, Cemalettin(22)
- Gücer, Mehmet Ali(22)
- Günen, Mehmet Akif(22)
- Kankal, Murat(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(20)
- Kurnaz, Muammer(19)
- Tuncer, Metin(19)
- Yolcu, Halil(19)
- Çelik, Necati(19)
- Ürkek, Bayram(19)
- Şan, Murat(19)
- Aliyazicioglu, Yuksel(18)
Yayınlar
- MakaleYalnız künye2018Scopus SJRQ1The Fabrication and MOSFET-Only Circuit Implementation of Semiconductor Memristor
Babacan, Yunus; Yesil, Abdullah; Gul, Fatih
In this paper, a ZnO-based semiconductor thin film memristor (300 nm in thickness) device is fabricated using metallic top and bottom electrodes by direct-current reactive magnetron sputter. The memristive characteristics of the device were completed by time-dependent current-voltage (I-V-t) measurements, and the typical pinched hysteresis I-V loops of the memristor were observed. This paper is continued with the designing memristor emulator circuit, which has only four MOS transistors. The proposed circuit is suitable both for emulating the fabricated memristor and for using general memristor-based applications. Any circuit blocks such as a multiplier or active element are not used in the circuit to obtain memristive characteristics. All results of the proposed memristor emulator circuit are compatible with general characteristics of the fabricated semiconductor device. The MOSFET-based proposed memristor emulator circuit is laid out in the Analog Design Environment of Cadence Software using 180-nm TSMC CMOS process parameters and its layout area is 366 μm2. So as to show its performance, the dependences of the operating frequency and process corner as well as effects of radical temperature changes have been investigated in the simulation results section.
AtıfScopus94WoS77OpenAlex98
İncele - BildiriAçık Erişim2018Performance and degradation analyses of two different pv modules in central anatolia
Ozden, Talat; Akinoglu, Bulent G.; Kurtz, Sarah
Ankara (latitude: around 40°N) is in Central Anatolia and the climate is dry continental. Due to the rapid transition to renewable energy policies of Turkey it is now a must to complete truthful feasibility analyses for solar power systems countrywide. Long term performance and degradation analyses have been carried out by the authors for three different arrays and many research results appearing in the literature are summarized. Present research analyzes the outdoor testing results of two PV modules monthly data. One of the modules has multi crystalline silicon (Poly-Si) cells and the other is thin film silicon (amorphous Si / microcrystalline Si tandem structure - a-Si/μc-Si) cells. The results showed that in five years the average yearly efficiency decreases from 14% to 11% for Poly-Si (14.72% is the nameplate Standard Test Condition (STC) efficiency) and from 8% to 6% for thin film modules (9.15% is STC efficiency). Our calculations are based on measured solar global-horizontal irradiance from which we calculated plane-of-array irradiation using an anisotropic sky model. We present the details of these analyses and degradation rates for the two types of modules to be used in long term feasibility analyses.
AtıfScopus11OpenAlex10İncele - MakaleYayıncıda açık erişim2018Scopus SJRQ2Finite difference method for bitsadze-samarskii type overdetermined elliptic problem with dirichlet conditions
Ashyralyyev, Charyyar; Akyuz, Gulzipa
In this paper, we apply finite difference method to Bitsadze-Samarskii type overdetermined elliptic problem with Dirichlet conditions. Stability, coercive stability inequalities for solution of the first and second order of accuracy difference schemes (ADSs) are proved. Then, established abstract results are applied to get stable difference schemes for Bitsadze-Samarskii type overdetermined elliptic multidimensional differential problems with multipoint nonlocal boundary conditions. Finally, numerical results with explanation on the realization in two dimensional and three dimensional cases are presented.
AtıfScopus10WoS7OpenAlex11İncele - BildiriAçık Erişim2018Stress Analysis and Fatigue Behaviour of PTFE-Bronze Layered Journal Bearing under Real-Time Dynamic Loading
Duman, M.S.; Kaplan, E.; Cuvalci, O.; Hamamci, M.; Gocer, A.; Karamis, M.B.; Nair, F.; Savas, S.
The present paper is based on experimental studies and numerical simulations on the surface fatigue failure of the PTFE-bronze layered journal bearings under real-time loading. 'Permaglide Plain Bearings P10' type journal bearings were experimentally tested under different real time dynamic loadings by using real time journal bearing test system in our laboratory. The journal bearing consists of a PTFE-bronze layer approximately 0.32 mm thick on the steel support layer with 2.18 mm thick. Two different approaches have been considered with in experiments: (i) under real- time constant loading with varying bearing widths, (ii) under different real-time loadings at constant bearing widths. Fatigue regions, micro-crack dispersion and stress distributions occurred at the journal bearing were experimentally and theoretically investigated. The relation between fatigue region and pressure distributions were investigated by determining the circumferential pressure distribution under real-time dynamic loadings for the position of every 10° crank angles. In the theoretical part; stress and deformation distributions at the surface of the journal bearing analysed by using finite element methods to determine the relationship between stress and fatigue behaviour. As a result of this study, the maximum oil pressure and fatigue cracks were observed in the most heavily loaded regions of the bearing surface. Experimental results show that PTFE-Bronze layered journal bearings fatigue behaviour is better than the bearings include white metal alloy.
AtıfScopus4WoS5OpenAlex5İncele - MakaleYalnız künye2018Scopus SJRQ1Experimental study on cement-treated and untreated RAP blended bases: Cyclic plate loading test
Seferoğlu, Ayşegül Güneş; Seferoğlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The asphalt surrounding the reclaimed asphalt pavement (RAP) aggregates decrease the performance characteristics of road layers. RAP material increases the permanent deformation potential of road layers under the traffic load. In this study, the performances of RAP-VA (Virgin aggregate) mixtures was tested using cyclic plate loading test by adding pozzolanic cement into mixtures in order to use RAP material at the rate of 100% and to minimize the permanent deformation in plant-mix base courses (PBC). The permanent surface deformations of base course were measured at different points throughout 100 loading cycles and all of the measurements were compared to that of base course prepared from 100% VA. The effect of RAP/cement rate of mixtures on the permanent deformations was examined and it was determined that the increase in RAP rate increased the permanent deformations but cement significantly decreased it. Moreover, considering the material costs of mixtures, the cost analysis was performed and the profit margins that using RAP and cement offers to constructors were computed.
AtıfScopus24WoS22OpenAlex25İncele - MakaleAçık Erişim2018Scopus SJRQ4Single production of the excited muons at the SPPC-based ultimate μp collider
Cąliskan, Abdullatif
Single production potential of the excited muons at the SPPC-based ultimate muon-proton collider with center-of-mass energy of 116.6 TeV was analyzed. We calculated the production cross-sections and the decay widths of the excited muons with the process of μp → μX → γμX. We obtained the normalized transverse momentum and pseudorapidity distributions of the final-state particles to attain the kinematical cuts for the discovery of the excited muons. With these cuts, we determined the mass limits. It was shown that the discovery limits on the mass of the excited muons are 19.6 and 10.1 TeV for λ = mμ and λ=50 TeV, respectively.
AtıfScopus3WoS3OpenAlex4TR Dizin2
İncele - MakaleYalnız künye2018Scopus SJRQ3Modeling of Co(II) adsorption by artificial bee colony and genetic algorithm
Öztürk, Nurcan; Sentürk, Hasan Basri; Gündogdu, Ali; Duran, Celal
In this work, it was investigated the usability of artificial bee colony (ABC) and genetic algorithm (GA) in modeling adsorption of Co(II) onto drinking water treatment sludge (DWTS). DWTS, obtained as inevitable byproduct at the end of drinking water treatment stages, was used as an adsorbent without any physical or chemical pre-treatment in the adsorption experiments. Firstly, DWTS was characterized employing various analytical procedures such as elemental, FT-IR, SEM-EDS, XRD, XRF and TGA/DTA analysis. Then, adsorption experiments were carried out in a batch system and DWTS's Co(II) removal potential was modelled via ABC and GA methods considering the effects of certain experimental parameters (initial pH, contact time, initial Co(II) concentration, DWTS dosage) called as the input parameters. The accuracy of ABC and GA method was determined and these methods were applied to four different functions: quadratic, exponential, linear and power. Some statistical indices (sum square error, root mean square error, mean absolute error, average relative error, and determination coefficient) were used to evaluate the performance of these models. The ABC and GA method with quadratic forms obtained better prediction. As a result, it was shown ABC and GA can be used optimization of the regression function coefficients in modeling adsorption experiments.
AtıfScopus5WoS4OpenAlex4İncele - MakaleAçık Erişim2018Scopus SJRQ1Resistance of Axially Loaded T- and X-Joints of Elliptical Hollow Sections at Elevated Temperatures – A Finite Element Study
Ozyurt, E.; Wang, Y.C.
This study presents the results of a numerical study to develop a method to calculate the static strength of welded Elliptical Hollow Section (EHS) joints at elevated temperatures. Extensive numerical simulations using the non-linear finite element package, ABAQUS v6.14–1 on EHS T- and X-joints under brace axial compression or tension and pre-stress in chord member with different type of joint orientations at elevated temperatures over a wide range of diameter ratio have been conducted. The adjustments required to be made to the equations of joint resistance under ambient temperature conditions for estimating joint resistance at elevated temperature conditions are investigated in this study. The FE simulation results have been compared with the calculation results of a number of existing methods at ambient temperature. It has been found that the method proposed by Packer et al. gives the best agreement with the authors' simulation results at ambient temperature. At elevated temperatures, for T- and X- joints with braces in compression welded to the wide sides of chords, replacing the ambient temperature yield strength of steel by the elevated temperature value in the current design method overestimates the ultimate load carrying capacity of axially loaded EHS T- and X-joints due to inability of the ambient temperature calculation equations to take into consideration EHS flattening at high temperatures. For these cases, it is recommended to calculate the joint strength reduction factor at elevated temperatures according to the Young's modulus of steel.
AtıfScopus21WoS18OpenAlex22İncele - MakaleAçık Erişim2018Scopus SJRQ3Radii of uniform convexity of some special functions
Aktaş, Ibrahim; Toklu, Evrim; Orhan, Halit
In this investigation our main aim is to determine the radii of uniform convexity of selected normalized q -Bessel and Wright functions. Here we consider six different normalized forms of q -Bessel functions and we apply three different kinds of the normalization of the Wright function. We also show that the obtained radii are the smallest positive roots of some functional equations.
AtıfScopus12WoS14OpenAlex15İncele - BildiriYalnız künye2018Power spectrum analysis of EEG for watching 2D & 3D videos and resting state
Manshouri, Negin; Maleki, Masoud; Kayikcioglu, Temel
Analysis of the brain waves has become useful over than 80 years. Along with the medical application, the brain signal is also used for other research works in the last fifteen years. In this study, by considering the depth factor in the image of a video, the effects of it are checked on EEG. A video is displayed in two-dimensional (2D) and three-dimensional (3D) format to the subjects. After recording the EEG signals in video watching, the resting state was recorded. Three states are considered for a better understanding of these effects on EEG. These states involve 2D&3D, 2D&resting and 3D&resting. Frequency analysis of the signals is evaluated by two methods. These methods are Fast Fourier Transform (FFT) and Welch method.
AtıfScopus2WoS1OpenAlex3İncele - MakaleYalnız künye2018Scopus SJRQ2Multipath interference cancelation in GPS time series under changing physical conditions by means of adaptive filtering
Üstün, Aydın; Yalvaç, Sefa
Multipath, a highly autocorrelated signal is observable phenomena during time periods longer than the sidereal period of Global Positioning System (GPS) satellites in their constellations. Multipath pattern and sidereal repeat time interaction are examined in terms of time series correlations of topocentric coordinates using GPS code and phase observations collected at high and low frequencies. The horizontal and vertical components at 5 and 30 s sampling rates are analyzed to detect and remove multipath classified by their MP1 levels and baseline lengths. For the selected 11 stations that have 24-hour data from CORS stations in the USA and Turkey, the repeat times of the GPS constellation were identified as a function of maximum cross-correlation of adjacent time series. The multipath interference signal from two-day time series data is removed by an adaptive filter to improve time series of coordinate estimates. After the filtering process, an effective epoch based position tracking has been accomplished, especially in the height component. The position errors disappeared to maximum possible extent in the pseudo-range measurements. Up to 70% improvement for the phase derived coordinates in reflective environment has been achieved over the baselines ranging from 1 km to 175 km. For the phase observables, the filter success directly related to the multipath level which is specific to the station.
AtıfScopus3WoS2OpenAlex4İncele - MakaleYalnız künye2018Scopus SJRQ3A novel hybrid approach for simplified neutrosophic decision-making with completely unknown weight information
Küçük, Gökçe Dilek; Şahin, Rıdvan
The simplified neutrosophic set (SNS) is a useful model to describe the indeterminacy information which widely exists in the real world. In this paper, we develop a multicriteria decision-making (MCDM) method under simplified neutrosophic environment in which the information about weights of criteria is completely unknown, and the decision criterion values take the form of simplified neutrosophic numbers (SNNs). In order to determine the weighting vector of the criteria, we establish an optimization model based on the basic ideal of the traditional gray relational analysis (GRA) method. By solving this model, we get a simple and exact formula which can be used to determine the criterion weights. Moreover, we utilize the dice similarity measure to determine the similarity measures between each alternative decision and the related ideal decisions. Then, based on the traditional GRA method and the technique for order preference by similarity to ideal solution (TOPSIS), some calculation steps are presented for solving a simplified neutrosophic multicriteria decision-making problem with completely unknown weight information. To avoid information loss, this model does not use the aggregation process of decision information. Comparisons of the suggested methodology with other methods are also made. Finally, a numerical example and an experimental analysis are proposed to illustrate the application of the proposed model.
AtıfScopus5WoS5OpenAlex6İncele - MakaleYalnız künye2018Scopus SJRQ2Determination of certain properties of scotch pine (Pinus sylvestris L.) wood which is impregnated with boron compounds and Quechua
Sen, Selim; Said Fidan, M.; Alkan, Elif; Sadiye Yaşar, S.
As the industrialisation and technological developments increase; the search for functional material which is environment-friendly, non-toxic, flame resistant, with a broad applicability and with high-temperature endurance also increases. Even though the wood material corresponds most of these features, its possession of an organic structure causes it to be affected negatively by damages occurring under proper conditions in the outdoor environment. Due to this reason, this study is conducted to prevent damages (biotic, abiotic pests, fire, etc.) caused by the environment to the wooden material, and to determine some physical and mechanical properties of wooden material impregnated with quechua, borax and boric acid, which are used to extend the usage life. Those features are needed in an outdoor environment. The Scotch pine (Pinus sylvestris L.) test specimens are prepared with borax, boric acid, borax+boric acid, from borax compounds, which have a great potential in Turkey, and with quechua, one of the natural impregnation substances. Then these samples are impregnated with three different (1%, 3%, 5%) solution concentrations according to ASTM 1413-76 standards and some physical-mechanical property changes are investigated. After impregnation, samples are tested and compared with control samples. According to the test results; the lowest oven dried density change is obtained in borax as 0.46 g . cm -3 in terms of boron compounds and the retention amount is determined to be highest with 3.83 kg.m -3 in the samples impregnated with boric acid. The bending strength and elastic modulus are found to be highest with 83.53 MPa and 10281 MPa in the samples impregnated with boric acid. When examined at the concentration level, it is determined to be highest with 81.89 MPa in samples with 3% concentration. There are statistical discrepancies with 55.77 MPa in the comprehensive strength parallel to grain in boric acid in terms of boron compounds.
AtıfScopus4WoS4İncele - Kitap BölümüYalnız künye2018Strategic communication management in Turkey
Taşdemir, Erdem; Aslan, Emre Ş.
- Kitap BölümüYalnız künye2018A study on rhetoric theory and rhetoric use in advertisement
Aslan, Emre Ş.; Demirel, Çağatay
- MakaleYalnız künye2018Scopus SJRQ4Determination of Late Embryonic Death Rates by Pregnancy Associated Glycoproteins and Rectal Examination in Cows
Paksoy, Zahid
In this study, it was aimed to make the pregnancy diagnosis with the determination of glycoproteins (PAG) associated pregnancy after insemination in the cows, and to determine the late embryonic mortality rates. As material, 2919 head cows in different races and ages were used in farms and family businesses in Kahramanmaraş province. Milk sample was taken on the 25–30 day after artificial insemination from cows. The level of PAG in these milk samples was analyzed by using the Milk Pregnancy Test Kit for cows. This kit was used according to the manufacturer's instructions. During the study, it was determined that 1660 cows were pregnant, 188 were suspicious and 1071 were not pregnant. The pregnant animals were examined by rectal palpation on the 50th day when their pregnancy was continued. Controls performed on the 50th day of pregnant cows showed that 1623 cows were still pregnant and 37 cows had late embryonic deaths. As a result, early pregnancies can be accurately detected by measuring the level of PAG in the cow's milk using the Milk Pregnancy Test Kit. It was concluded that late embryonic mortality rates could be detected and that this analysis could be used routinely.
- Kitap BölümüYalnız künye2018Human’s tragedy in the global world
Çıvgın, Ayşe Gül; Özsoy, Seda
- MakaleYalnız künye2018Scopus SJRQ2Testing twin deficits hypothesis for Eu-27 and Turkey: A panel granger causality approach under cross-sectional dependence
Bölükbaş, Mehmet; Topal, Mehmet Hanefi; Hotunluoğlu, Hakan
Twin deficits hypothesis has been one of the most widely-applied phenomenon in the economics literature. In this study, the twin deficits hypothesis was tested for the EU-27 member states and Turkey with the data covering the 2002:Q1-2014:Q1 period. Unlike other studies, the twin deficits hypothesis was tested by using second generation panel causality tests that considered the cross-sectional dependence. According to the findings of this study, which used panel Granger causality tests suggested by Dumitrescu-Hurlin (2012) and Emirmahmutoğlu-Kose (2011), there is statistically significant bidirectional causality between budget deficit (BD) and current account deficit (CAD) in the relevant period. It was found out a bidirectional causality between BD and CAD in sixteen of the twenty-eight countries (Austria, Belgium, Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Italy, Netherlands, Romania, Spain, Turkey and the UK) and a unidirectional causality from BD to CAD was also noticed in five EU countries (Cyprus, Latvia, Lithuania, Poland and Slovakia). Nevertheless, the findings indicated that there is a unidirectional causality from CAD to BD in Hungary, Luxembourg and Malta but there is no causality between BD and CAD in Ireland, Portugal, Slovenia, and Sweden.
AtıfScopus6WoS5İncele - MakaleAçık Erişim2018Student views on using smart boards in turkish education
Kırbaş, Abdulkadir
One of the greatest opportunities for technological developments in the field of education is computer aided smart boards. Our country has adapted to these technological developments and initiated the smart board applications with FATIH Project which is one of the few projects of its size of the world. The aim of this research is to reveal the contribution of smart boards – which are the most important elements of the FATIH project-to Turkish education, their effects on student motivation, and also their negative aspects by taking the views and opinions of students who are directly involved in the project. The sample of the research consists of 600 students studying in Yakutiye, Palandöken and Aziziye districts of Erzurum province in the Fall semester of 2017-2018 academic year. Based on the results of the research, it was found that thanks to using smart boards in Turkish education lessons, the students understood Turkish better, learned the course subjects easily, were more successful in Turkish, the visual and audio materials used in smart board applications were beneficial in better understanding the topic, students had the opportunity to learn the topics from more and various sources, smart boards made the lessons fun and enjoyable, increased interest for the lessons, students liked using the smart boards, smart boards had positive effects on learning and student motivation; whereas some negative opinions were also found that some students had difficulties using smart boards, frequent malfunctions in the smart boards caused a loss of time in lessons, students were not willing to prepare homework that included the use of smart boards, visual quality of the boards was low, and smart boards made the students more lazy.
AtıfScopus9OpenAlex10İncele - BildiriAçık Erişim2018Daily and monthly module temperature variation for 9 different modules
Özden, Talat; Tolgay, Doga; Akinoglu, Bulent G.
One of the main parameter affecting the efficiency of PV modules is the module temperature. In this respect, outdoor testing of modules is very important to determine the temperature dependent performances and degradation rates. In this work, we analyzed the module temperatures of 9 different modules tested in the outdoor testing facility of METU-GUNAM, Ankara (latitude ∼40°N, in Central Anatolia and the climate is dry continental). The tested module types are two CIS (identical), one μc-Si/a-Si, one Poly-Si, three Mono-Si (two identical), one HIT and one bifacial. The module temperatures can reach up to 76°C while the ambient is around 39 °C during summer days. Monthly average module temperatures can reach up to 33.7°C (CIS) while the monthly average ambient is at 26.0°C and drops down to 1 °C while average ambient temperature is about the same as average module temperature. The results showed that the monthly averages of module temperatures differences are maximum during summer (∼3.5°C) and minimum during winter (1.1°C). It is interesting that the two CIS modules have the highest monthly average module temperature and although they are supposed to be identical their temperatures differ significantly. Bifacial and HIT module temperatures are lower than the Mono-Si modules. One of the two identical Mono-Si modules was not cleaned and its module temperature is always lower than the one that was cleaned periodically, as expected. In this work, we also present the results and discussions on the spatial variations of measured module temperatures of PV panels.
AtıfScopus6OpenAlex6İncele