Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Günaydin, Murat(6)
- Ak, Muammer(5)
- Akinoglu, Bulent G.(5)
- Akpinar, Muhammet Vefa(5)
- Genç, Ali Fuat(5)
- Kahraman, Yakup(5)
- Takaoğlu, Zeynep Başkan(5)
- Acet, Tuba(4)
- Aliyazicioglu, Yuksel(4)
- Altunişik, Ahmet Can(4)
- Ashyralyyev, Charyyar(4)
- Bölükbaş, Mehmet(4)
- Dağ, Serhat(4)
- Demir, Selim(4)
- Kaygusuz, Abdullah(4)
- Kayikçioglu, Temel(4)
- Okur, Fatih Yesevi(4)
- Ozden, Talat(4)
- Topal, Mehmet Hanefi(4)
- Turan, Ibrahim(4)
- Adanur, Süleyman(3)
- Akdu, Uğur(3)
- Aksakal, Vecihi(3)
- Aktaş, Ibrahim(3)
- Arslan, Mehmet(3)
- Ashyralyev, A.(3)
- Aslan, Emre Ş(3)
- Aydin, Orhan(3)
- Duran, Celal(3)
- Düzgün, Azer Özad(3)
- Gul, Fatih(3)
- Güllüpunar, Hasan(3)
- Karahasan, Olguhan Şevket(3)
- Kaya, Yusuf(3)
- Lukashov, A.(3)
- Nizetic, S(3)
- Orhan, Halit(3)
- Ozcan, Kadriye(3)
- Paksoy, Zahid(3)
- Papadopoulos, A(3)
Yayınlar
- MakaleYalnız künye2018Antioxidant potential of rosehip seed extract in stabilisation of flaxseed oil
Ilyasoglu, H.
The aim of this study was to evaluate the usage of rosehip seed powder (RSP) extract in flaxseed oil to retard lipid oxidation. The acetone extract of the RSP (500 mg kg-1; 1000 mg kg-1) was used. Synthetic antioxidant BHT (200 mg kg-1) was added into the flaxseed oil to evaluate the antioxidant potential of the RSP extract. The peroxide value (PV), TBARS value, and p-anisidine value (p-AV) of the flaxseed oil were analysed during 12 days of storage. The total oxidation (TOTOX) value was also calculated. The sample with the RSP (500 mg kg-1; 1000 mg kg-1) generally showed lower PV, p-AV, and TOTOX value than the control sample and sample with the BHT. These results indicated that the RSP may be used in edible oils to prevent lipid oxidation as a source of natural antioxidants.
- BildiriAçık Erişim2018Thermal modeling and verification of pv module temperature and energy yield using outdoor measurements for Ankara, Turkey
Tuncel, Bilge; Akinoglu, Bulent G.; Ozden, Talat; Balog, Robert S.
Ankara is in the Central Anatolia region of Turkey where the climate is dry-continental with an annual solar insolation of around 1750 kWh/m 2 . In the transition to renewable energy, detailed analyses are required to ensure effective and economic utilization of the available solar resource. An essential part of these analyses is to calculate expected energy yield. For photovoltaic (PV) systems, this includes the effect of temperature on the PV efficiency, which determines the power yield of the PV modules. In this study, a first-principles thermal modeling approach is improved by adding the speed and direction of wind across the PV module into a forced convection term as well as including the temperature dependency of the module conversion efficiency. The analytical model is based on the principle of conservation of energy and uses meteorological data that are readily available from most state meteorological services. The mathematical analysis is suitable to predict the performance of a proposed PV installation without the time and expense of installing and monitoring a pilot system. The mathematical model is compared against measured data from the METU-GUNAM Outdoor Test Facility in Ankara to validate the methodology. Preliminary analyses showed that the model performs well especially during sunrise and sunsets shoulders of the diurnal cycle with a deviation of only a few W/m 2 for the electrical power yield and about 2°C for the module temperature. However, these deviations could become as large as 12 W/m 2 and 8°C at solar noon which suggests that the model still requires further improvement. In general, this error was found to be less that obtained by using basic explicit correlation methods and offers the advantage that it can be used for other geographical environments for which insolation and meteorological data is available without needing to construct a test-site.
- MakaleYalnız künye2018Galileo satellite data contribution to GNSS solutions for short and long baselines
Yalvac, S.; Berber, M.
GALILEO (Europe's Global Navigation Satellite System) is going full speed ahead to achieve full constellation by 2020. Since GALILEO is currently an emerging system, the contribution of these satellites to GNSS (Global Navigation Satellite System) solutions needs to be investigated. For this purpose, GNSS data collected at three IGS (International GNSS Service) MGEX (Multi GNSS Experiment) stations are analyzed. For the analyses, GPS (Global Positioning System) only, GLONASS (Russia's Global Navigation Satellite System) only, GALILEO-only and combined solutions are tested and also effect of baseline length is examined. The results indicate that compared to GPS, GLONASS and ALL (GPS + GLONASS + GALILEO) solutions, GALILEO results vary greatly. When GALILEO observations are combined with other observations, the precision goes down. That is to say, for short baseline solution, GALILEO results fluctuate around 1 cm in the horizontal plane and in the vertical plane variations are mostly within 3–5 cm. For long baseline solution, GALILEO results are going up and down in the horizontal between 2 and 3 cm and in the vertical roughly 10 cm. In terms of accuracy, for short baseline solution, GALILEO-only solution is close to GPS-only solution; yet, we cannot say the same thing for long baseline solution.
- BildiriAçık Erişim2018Well-posedness of Neumann-type elliptic overdetermined problem with integral condition
Ashyralyyev, Charyyar; Çay, Aysel; Ashyralyev, A.; Sadybekov, M.; Lukashov, A.
The current paper is devoted to overdetermined elliptic problem with integral condition for derivatives. This overde-termined problem is converted to auxiliary nonlocal boundary value problem (ANBVP) with integral boundary condition. Well-posedness of abstract problem is established. Then, obtained results are used to obtain stability inequalities for solution of three Neumann-type inverse elliptic problems with integral condition to multidimensional differential equation.
- MakaleYalnız künye2018The effects of 4-Vinylcyclohexene diepoxide on gene expression in dog testes
Paksoy, Zahid
In this study, the effects of 4-Vinylcyclohexene diepoxide (VCD) on the testicular gene expression in dogs were investigated. Eighteen male dogs were used as material and were randomly allocated to 3 groups. The first group (n=6) was administered sesame oil by intraperitoneal (i.p.) route once a day for 8 days, and this group was served as a control. The second group (n=6) received 80 mg/kg VCD and the third (n=6) group was administered VCD (i.p.) at a dose of 320 mg/kg once daily for 8 days. The testes were removed on following day the last VCD administration. The testes were immediately placed in the RNA stabilization solution and stored at -20°C. Later mRNAs were obtained from tissue samples. After RNA isolation, the cDNAs were synthesized. Finally, MasterMix was prepared and gene expression levels were examined at the real-time PCR. The expression of B cell lymphoma 2 (Bcl-2), tumor suppressor protein (tp53), Bax, CASP2, CASP3, CASP8, CASP9 and β-actin were investigated in the all groups. Cross-group comparisons were made by using student t test. The tp53 gene expression in the second group was found to be higher compared to the control group. It was determined that the expression of Bcl-2 was reduced in the testes of animals treated with high-dose VCD. CASP-3 was found to be more expressed and CASP-9 was down-regulated in the third group. In addition, CASP-8 gene expression was significantly reduced in both treatment groups. As a result, it can be concluded that expression changes in the tp53, Bcl-2, CASP-3, CASP-8 and CASP-9 genes in the testes of male dogs may cause apoptotic changes with the VCD application.
- MakaleYalnız künye2018The 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.
- 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.
- MakaleYayıncıda açık erişim2018Finite 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.
- 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.
- MakaleYalnız künye2018Experimental 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.
- MakaleAçık Erişim2018Single 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.
- MakaleYalnız künye2018Modeling 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.
- MakaleAçık Erişim2018Resistance 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.
- MakaleAçık Erişim2018Radii 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.
- 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.
- MakaleYalnız künye2018Multipath 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.
- MakaleYalnız künye2018A 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.
- MakaleYalnız künye2018Determination 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.
- 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