Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(87)
- Merdan, Mehmet(70)
- Duran, Celal(56)
- Baltaci, Cemalettin(52)
- Kulakaç, Nurşen(51)
- Ozdes, Duygu(51)
- Kaygusuz, Abdullah(47)
- Öztürk, Serkan(42)
- Demir, Selim(40)
- Karsli, Orhan(37)
- Turan, Ibrahim(37)
- Dokuz, Abdurrahman(36)
- Gücer, Mehmet Ali(36)
- Sipahi, Ferkan(36)
- Araz, Onur(35)
- Kandemir, Raif(31)
- Vural, Alaaddin(31)
- Topal, Fevzi(30)
- Kurt, Kemal(29)
- Ürkek, Bayram(29)
- Maden, Nafiz(28)
- Acet, Tuba(27)
- Alemdag, Selcuk(26)
- Arslan, Mehmet(26)
- Ayaydin, Hasan(26)
- Akaryali, Enver(25)
- Aydin, Faruk(25)
- Baltacı, Cemalettin(25)
- Yücel, Cem(25)
- Akar, Zeynep(24)
- Barut, Abdulkadir(24)
- Ozturk, Samet(24)
- Pala, Fahrettin(24)
- Peker, Iskender(24)
- Topal, Meryem(24)
- Yildiz, Salih(24)
- Öz, Mehmet(24)
- Aliyazicioglu, Yuksel(23)
- Bostan, Sedat(23)
- Kankal, Murat(23)
Yayınlar
- MakaleYalnız künye2012Scopus SJRQ1Fast practical analytical model for analysis of backfill-rectangular tank-fluid interaction systems
Cakir, Tufan; Livaoglu, Ramazan
The paper describes a simple, efficient and reasonably accurate analytical model for analysis of backfill-rectangular tank-fluid interaction systems. The presented model uses Housner's two-mass approximation for fluid interaction and mass-spring-dashpot system for backfill interaction and accommodates a variety of features that may affect the behavior of rectangular tanks including fluid volume, backfill geometry, soil properties and flexible/rigid wall types. Unlike the conventional finite element and the finite difference models that require considerable effort and knowledge to prepare the input data, the proposed model requires only a few pieces of data to define the problem and control the analysis. A series of finite element simulations were also fulfilled on two real rectangular tanks subjected to backfill and fluid effects. A reasonably good accord was obtained comparing the analytical predictions to results from numerical simulations. Thus, it can be stated that the model may be used effectively to perform a broad suite of parametric studies at the design stage and also as a reliable tool for estimating the system behavior. The results obtained from parametric seismic analyses indicated that backfill interaction, wall flexibility and fluid interaction considerably affect the lateral displacements. The sloshing response, however, was not practically affected by the backfill interaction and the wall flexibility.
AtıfScopus24WoS23OpenAlex21
İncele - MakaleYalnız künye2012Scopus SJRQ3Spatial variations of precursory seismic quiescence observed in recent years in the eastern part of Turkey
Öztürk, Serkan; Bayrak, Yusuf
A statistical analysis is made for the eastern part of Turkey in the beginning of 2009 by studying the phenomenon of seismic quiescence as a potential precursor of the main shocks. The results produced four areas having seismic quiescence in the beginning of 2009. These areas are observed to be centered at 39.96°N-40.69°E (around Aşkale, Erzurum), 39.36°N-39.74°E (around Ovaci{dotless}k, Tunceli), 39.02°N-40.52°E (including Elazi{dotless}ǧ and Bingöl), and 38.45°N-42.94°E (Van Lake). Based on the recent results showing 5 ± 1.5 years quiescence before the occurrence of an earthquake in this region, the future earthquake would be expected between 2009. 5 and 2010. 5. The future earthquake occurrence may reach 2012 if we consider the standard deviation of average seismic quiescence as ±1.5 years. We have found that the MW = 6.0 Elazi{dotless}ǧ earthquake on 8 March 2010, followed a seismic quiescence starting about 5 years before the main shock. Thus, special interest should be given to the other regions where the seismic quiescence is observed.
AtıfScopus27WoS22OpenAlex30İncele - MakaleYalnız künye2012Scopus SJRQ1The total electricity energy production of the world, European Union, and Turkey: Projections and comparison
Akpinar, A.; Tavşan, F.; Kömürcü, Murat Ihsan; Filiz, M.H.; Kaygusuz, K.
This study aims to forecast the world's, European Union's (EU), and Turkey's electricity energy generation until 2030. For this purpose, the electricity energy sector of the world, EU, and Turkey was overviewed from past to present. The total electricity energy generation for the world, EU, and Turkey were then modelled by using historical energy generation data as years with regression analysis. Data from 1970 to 2004 for Turkey and data from 1980 to 2004 for the world and EU were used for the projections. Electricity energy productions have been forecasted up to year 2030. According to the results, it is determined that cubic (R2 = 0.997) and linear (R2 = 0.993) models for projection of the world's and EU's electricity energy generation, respectively, is fitness while the quadratic (R2 = 0.996) model fits for the projection of Turkey's total electricity energy generation and Turkey will have 0.995% of the world's electricity energy generation in 2030, while the EU will have 8.41% within the world's electricity energy generation in 2030 if the current trend continues.
AtıfScopus5WoS5OpenAlex8İncele - MakaleYalnız künye2012Scopus SJRQ1A-type granitoids from the Eastern Pontides, NE Turkey: Records for generation of hybrid A-type rocks in a subduction-related environment
Karsli, Orhan; Caran, Şemsettin; Dokuz, Abdurrahman; Çoban, Hakan; Chen, Bin; Kandemir, Raif
The Eastern Pontides is characterized by the many of intrusive bodies formed throughout the late Mesozoic-early Cenozoic. Most of these are I-type granitoids, but here, we present for the first time an A-type pluton from the region to assess source characteristics and geodynamic implications. The A-type Pirnalli pluton has a SHRIMP zircon U-Pb age of 81.2±1Ma. It is composed of granite, syenite and quartz monzonite, and its enclaves are monzonitic in composition with elevated Ga/Al ratios and low Mg# (<42). The pluton is dominantly metaluminous (A/CNK=0.88 to 1.00) and belong to shoshonitic and ultra-potassic series. The samples are highly enriched in LREE and show significant negative Eu (Eu/Eu *=0.33 to 0.92), Ba, Nb, Sr and Ti anomalies in the spidergrams. The host rocks and their enclaves posses quite similar Sr-Nd isotopic compositions (I Sr=0.70693 to 0.70736, ε Nd (81Ma)=-2.6 to -2.0, T DM=0.94 to 1.12Ga), pointing to a lower crustal parental magma with a minor contribution of lithospheric mantle. We hypothesize that upwelling of asthenosphere triggered melting of chemically enriched upper mantle and basic magma formed. Melting of lower crust was provided by the underplating of this basic magma. Mixing between lower crust- and mantle-derived melts at depths of lower crust appears to be most reasonable petrogenetic process responsible for generation of the pluton. Sr-Nd isotope modeling suggests mixing of 82-90% of the lower crustal-derived melt with ~10-18% of the mantle-derived melt. Then the hybrid melt ascended to shallower crustal level and underwent a limited fractionation process to generate a variety of rock types. Our data also suggest that the A-type Pirnalli pluton likely formed at an extensional environment of active continental margin throughout the late Cretaceous. Ongoing extension then led to opening of Black Sea as a back-arc basin further north of the Eastern Pontides.
AtıfScopus95WoS91OpenAlex97İncele - MakaleYalnız künye2012Scopus SJRQ2Aspirin, clopidogrel, and warfarin use and outcomes in a cohort of 580 patients discharged after hospitalization for decompensated heart failure
Kozdaǧ, Güliz; Yaymaci, Mehmet; Ertaş, Gökhan; Çelikyurt, Umut; Şahin, Tayfun; Kiliç, Teoman; Ural, Dilek
The benefits of taking of aspirin, clopidogrel, and warfarin in relation to cardiovascular mortality and re-hospitalization in chronic heart failure (HF) patients have been called into question. We examined the outcomes (cardiac mortality and/or HF re-hospitalization) in patients discharged from our hospital between January 2003 and July 2009 after hospitalization for chronic decompensated HF. Of 580 HF patients (mean age, 63 ± 13 years; mean ejection fraction, 26 ± 9%, 63% with coronary disease and 37% without coronary disease), 207 patients (36%) died due to cardiovascular reasons, and 313 (54%) required HF re-hospitalization for decompensated HF during a 39 ± 14 month follow-up period. 101 (17%) patients were taking clopidogrel during enrollment in the study. When comparing patients who were on clopidogrel treatment with those who were not, clopidogrel was found to have a beneficial effect on cardiac mortality (27 vs. 38%, P = 0.04). In conclusion, in this observational prospective study, patients who used clopidogrel showed decreased cardiac mortality [HR, 0.566 (95% CI 0.332-0.964), P = 0.036] compared to patients who did not take clopidogrel. Clopidogrel had a beneficial effect on the survival of chronic HF patients in the long term.
AtıfScopus10OpenAlex10
İncele - MakaleYalnız künye2012Scopus SJRQ3Synthesis and characterisation of new metallophthalocyanines containing four 12-membered diazadithia-macrocyclic moieties
Kaya, Elif Çelenk; Kantekin, Halit; Kaya, Afşin Ahmet; Dakoǧlu, Asuman; Öksüz, Sümeyra; Şişik, Hanife
Tetrasubstituted zinc, cobalt, nickel, copper and lead phthalocyanines bearing four 12-membered diazadithia macrocyclic moieties on peripheral positions have been synthesised by cyclotetramerisation reaction of 1,10-ditosyl-1,2,3,5,6,8,9,10-octahydrobenzo[h][1,4,7,10] dithiadiazacyclododecine-12,13-dicarbonitrile and corresponding anhydrous metal salts under microwave irradiation. The thermal stabilities of the phthalocyanine compounds have determined by thermogravimetric analysis.
AtıfScopus1WoS2OpenAlex1İncele - MakaleYalnız künye2012Scopus SJRQ3Yield and quality characteristics of sunflower silages in highlands
Guney, Erdal; Tan, Mustafa; Yolcu, Halil
This research was carried out to compare the yield and quality characteristics of four sunflower (Helianthus annuus L.) genotypes (i.e., confectionery Tekirdag landrace, confectionery Erzurum landrace, oilseed Sirena and oilseed C70165 hybrids) and one corn (Zea mays L.) genotype (i.e., SZE TC-S13 hybrid) in the Agriculture Faculty of Ataturk University in the east of Turkey during the period between 2005 and 2006. The study was designed in a randomized complete block design with five treatments replicated three times. The genotypes were evaluated in terms of forage properties as well as chemical and physical properties of silages in both years. According to the results, the corn genotype had better yield and silage qualities than sunflower genotypes. But crude protein contents of silages of sunflower genotypes were superior in comparison to the corn genotype. Also amongst sunflower genotypes, confectionery Tekirdag and Erzurum landraces had slightly higher silage qualities than oilseed sunflower hybrids.
AtıfScopus6WoS7İncele - MakaleYalnız künye2012Scopus SJRQ2Chaotic systems via multi-step differential transformation method
Yildirim, Ahmet; Gökdoǧan, Ahmet; Merdan, Mehmet
In this article, the multi-step differential transform method is implemented to give approximate and analytical solutions of nonlinear fractional order ordinary differential equation systems, such as Chen, Lorenz, Arneodo-Coullet, Genesio, Lui, and Rikitake chaotic systems. The numerical solutions obtained from the proposed method indicate that the approach is easy, simple, and accurate when applied to systems of fractional differential equations. Numerical simulations are given to verify the reliability and effectiveness of this method.
AtıfScopus20WoS11OpenAlex19İncele - MakaleAçık Erişim2012Scopus SJRQ2Dehydrated hazelnut husk carbon: A novel sorbent for removal of Ni(II) ions from aqueous solution
Sivrikaya, Sezen; Albayrak, Sinem; Imamoglu, Mustafa; Gundogdu, Ali; Duran, Celal; Yildiz, Hulya
The present study has been performed to examine the adsorption ability of novel sorbent dehydrated hazelnut husk carbon (DHHC) towards Ni(II) ions from aqueous solution using the batch adsorption technique. The effective factors such as initial pH of the aqueous solution, contact time, initial Ni(II) concentration, adsorbent dosage, and temperature were investigated. The studies were also conducted to understand the effect of some co-existing ions which may be present in aqueous solutions. DHHC showed good adsorption potential for Ni(II) ions. The optimum initial pH value was selected as 5.0. The experimental data fitted well to the Langmuir adsorption isotherm model. Among the kinetic models tested for the adsorption of Ni(II), the pseudo-second-order model showed a good fit of the kinetic data. The thermodynamic parameters including the Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) changes indicated that the adsorption of Ni(II) ions onto DHHC was feasible, spontaneous, and exothermic in the temperature range of 25-55°C. The results of this study showed the effectiveness and feasibility of DHHC for the removal of Ni(II) ions from aqueous solution.
AtıfScopus33WoS33OpenAlex33İncele - MakaleAçık Erişim2012Scopus SJRQ1Assessment of permeability and injection depth at the Atasu dam site (Turkey) based on experimental and numerical analyses
Gurocak, Zulfu; Alemdag, Selcuk
This study was performed in order to evaluate the permeability of the basalts and pyroclastics and the maximum depth of grout injection at the Atasu dam site, Turkey, using the equations of Kiraly and Hoek and Bray based on values obtained from Lugeon tests. In order to evaluate maximum discharge values and depth of injection, seepage analyses were performed using the finite element technique for each 10 m up to 100 m. The results indicate that to establish an impermeable zone at the dam site, the depth of injection should be taken as 50 m for the left and right slopes and 40 m for the river bed.
AtıfScopus45WoS37OpenAlex49İncele - MakaleAçık Erişim2012Scopus SJRQ2The difference problem of obtaining the parameter of a parabolic equation
Ashyralyyev, Charyyar; Demirdag, Oznur
The boundary value problem of determining the parameter p of a parabolic equation ′(t)+A(t)=f(t)+p(0≤t≤1),(0)=,(1)= in an arbitrary Banach space E with the strongly positive operator A is considered. The first order of accuracy stable difference scheme for the approximate solution of this problem is investigated. The well-posedness of this difference scheme is established. Applying the abstract result, the stability and almost coercive stability estimates for the solution of difference schemes for the approximate solution of differential equations with parameter are obtained.
AtıfScopus21WoS18OpenAlex16İncele - MakaleYalnız künye2012Scopus SJRQ3Elemental and radioactivity analyses of mosses collected in hatila valley national park - Eastern black sea region of Turkey
Koz, Bahadir; Cevik, Ugur; Celik, Necati
This study was performed in one of the most important parks of Turkey, the Hatila national park, where a gold mining activity is planned to be conducted. For this purpose, 40 moss samples were collected for heavy metal and radioactivity measurements. A radioisotope excited Xray fluorescence analysis using the method of multiple standard additions was applied for the elemental analysis of mosses collected in Hatila valley national park in the Eastern Black Sea region of Turkey. An annular 50 mCi 241Am radioactive source and annular 50 mCi 55Fe radioactive sources were used for excitation of characteristic K-X rays. An Si(Li) detector which had a 147eV full width at half maximum for 5.9 keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, tin and barium with average concentrations of 230, 5340, 450, 70, 4 and 33 mg.kg -1, respectively. 137Cs and 40K using gamma-ray spectroscopy were determined in 40 moss species collected from the Hatila valley national park. Average activity concentrations of 40K and 137Cs were found to be 103 and 272 Bq.kg -1, respectively. As the region was shown to be heavily contaminated by the Chernobyl accident, the high concentration of 137Cs could be due to this accident. The results are compared with those obtained in different parts of the world where gold mining activities are being conducted. The possible consequences of these results are briefly discussed from the point of potential hazards to ecology and human health.
AtıfScopus2WoS2İncele - MakaleYalnız künye2012Scopus SJRQ2Performance and emission studies of castor bean (Ricinus Communis) oil biodiesel and its blends with diesel fuel
Özcanli, M.; Serin, H.; Saribiyik, O.Y.; Aydin, K.; Serin, S.
An experimental study was conducted to evaluate the use of various blends of castor (Ricinus Communis) oil methyl ester with diesel fuel. Performance and exhaust emissions of castor oil biodiesel with diesel fuel in a commercial compression ignition engine were presented in this study. Biodiesel produced from castor oil was blended with diesel fuel at the volumetric ratios of 5% (B5), 10% (B10), 25% (B25), 50% (B50), and 100% (B100). Fuel properties of castor oil methyl ester and its blends with diesel fuel were stated. The performance results showed that blends of castor oil methyl ester with diesel provided an increase on brake specific fuel consumption and a small decrease on brake power output. Compared with diesel fuel, diesel-castor oil methyl ester blends showed that while the carbon monoxide and carbon dioxide emissions became reduced; the oxides of nitrogen emissions observed higher than diesel fuel emission characteristics. Test results showed that B25 was determined as a suitable alternative fuel for diesel engines.
AtıfScopus40WoS35OpenAlex39İncele - MakaleYalnız künye2012Scopus SJRQ1A study on the effects of high temperature on mechanical properties of fiber reinforced cementitious composites
Çavdar, Ahmet
The flexural strength and ductility properties of cementitious composites (mortar) under high temperature may be significantly improved by incorporating different types of fibers. In this study, four different types of fibers are added to cement mortars with the aim to investigate their mechanical contributions to mortars under high temperature, comparatively. Polypropylene (PP), carbon (CF), glass (GF) and polyvinyl alcohol (PVA) fibers are chosen for research. These fibers are added into mortars in five different ratios (0.0%, 0.5%, 1.0%, 1.50% and 2.0%) by volume. The mortars are subjected to the following temperatures: 21°C (normal conditions), 100°C (oven dry), 450°C and 650°C. The mechanical properties investigated are flexural strength, deflection and compressive strength of the cement mortars. In addition, thin sections of mortars are investigated to obtain changes in mortar because of high temperature. It is concluded that all fiber types contribute to the flexural strengths of mortars under high temperature. However, this contribution decreases with an increase in temperature. The samples with PVA show the best flexural performance (75-150%) under high temperature. CF which does not melt under high temperature also gives high flexural strength (11-85%). The compressive strengths of the mortars reduce under high temperature or with fiber addition. The highest increase in flexural strength and the lowest decrease in compressive strength is at 0.5-1.5% for CF if all temperature conditions are taken into consideration. The optimum fiber addition ratios of the samples containing PP and GF are 0.5% by volume. And for PVA, it is between 0.5% and 1.5% by volume.
AtıfScopus173WoS152OpenAlex178İncele - MakaleAçık Erişim2012Scopus SJRQ2Determination of the dependence of HPGe virtual point detector location on source dimensions in 60 keV-2 MeV range using Monte Carlo simulation
Çelik, N.
The virtual point detector (VPD) concept for an HPGe detector with 55% relative efficiency was confirmed for bulky sources having different diameters and heights. After reproducing experimental data, Monte Carlo simulation was used to investigate the dependence of VPD location on photon energy for various source diameters and heights in the energy range from 60 keV to 2 MeV. The simulations were confirmed using a soil reference source prepared by International Atomic Energy Agency (IAEA). It was seen that increasing photon energy makes significant changes in VPD location up to 600 keV. It was observed that VPD locations increase with increasing source diameter and height. It was also seen that VPD locations were approximately linearly dependent on source diameters and heights.
AtıfScopus5WoS5OpenAlex6İncele - MakaleYalnız künye2012Scopus SJRQ4Artificial neural networks for estimation of temporal rate coefficient of equilibrium bar volume
Kankal, Murat; Kömürcü, Murat Ihsan; Yüksek, Ömer; Akpinar, Adem
Present study consists the growth of a bar profile caused by cross-shore sediment transport. This is especially on growth of bar volume (V) toward equilibrium bar volume (Veq). Three analysis methods being a power and linear regression analysis (PRA and LRA) and an Artificial Neural Network (ANN) analysis were performed to determine empirical temporal rate coefficient (α). Forty-two experimental data were used for training set and the rest of the experimental data were used for testing set in the ANN analysis. As the results of analyses, the smallest average relative and root mean square error (RMSE) computed for the ANN methods are 7.578% and 0.029, respectively. It has been obtained that the ANN analysis, which is used for determination of α coefficient, gives reasonable results. Finally, bar volumes were calculated by means of computed α values and compared with the results of experimental data.
AtıfScopus3WoS5İncele - MakaleAçık Erişim2012Scopus SJRQ3Numerical approximations to the solution of ray tracing through the crystalline lens
Yildirim, A.; Gökdogan, A.; Merdan, M.; Lakshminarayanan, V.
An approximate analytical solution in the form of a rapidly convergent series for tracing light rays through an inhomogeneous graded index medium is developed, using the multi-step differential transform method based on the classical differential transformation method. Numerical results are compared to those obtained by the fourth-order Runge - Kutta method to illustrate the precision and effectiveness of the proposed method. Results are given in explicit and graphical forms.
AtıfScopus7WoS5OpenAlex6İncele - MakaleYalnız künye2012Scopus SJRQ2The effect of adding sour cherry pulp into yoghurt on the physicochemical properties, phenolic content and antioxidant activity during storage
Şengül, Memnune; Erkaya, Tuba; Şengül, Mustafa; Yildiz, Hilal
This study investigated the effect of adding sour cherry pulp into yoghurt on its physicochemical properties, phenolic content, antioxidant activity and sensory characteristics. Sour cherry pulp was added at 0%, 8%, 12% and 16% into the yoghurt, and measures were checked through 14days cold storage. The increasing sour cherry pulp concentration in yoghurt resulted in increasing pH and whey separation, whereas the values of the other parameters, total solid, fat, protein, ash, titratable acidity and viscosity decreased. During storage, total phenolic contents and antioxidant activity in yoghurts ranged from 20 to 81μg gallic acid equivalent per mg of sample and from 48% to 86%, respectively.
AtıfScopus48WoS44OpenAlex63İncele - MakaleYalnız künye2012Scopus SJRQ1Two-Dimensional Geothermal Modelling Along the Central Pontides Magmatic Arc: Implications for the Geodynamic Evolution of Northern Turkey
Maden, Nafiz
The Pontides, which can be divided tectonically into three main segments as Eastern, Central, and Western Pontides, is one of the most complex geodynamic settings within the Alpine belt. The Central Pontides, where the Eastern and Western Pontides met and formed a tectonic knot, represent an amalgamated tectonic mosaic consisting of remnants of oceanic, continental, and island arc segments. Subduction polarity, which is responsible for the formation of the Pontides, is still under debate because of limited geological, geophysical, and geochemical data. Two-dimensional (2-D) thermal modelling studies along the Central Pontides magmatic arc (Northern Turkey), Sakarya and Ki{dotless}rşehir continents are investigated in order to delineate the crustal thermal structure and subduction polarity. The obtained numerical results indicate that arc and back-arc regions are hot because of the cooling effects of a subducting plate. Moho temperatures in the investigated region are found between 992°C in the south (back-arc) and 415°C in the north (arc). Moreover, mantle heat flow values vary from 57.2 mWm -2 in the south (back-arc) to 34.7 mWm -2 in the north (arc). It is shown from this study that the Eurasia plate had moved from north to south under the Anatolia plate along the south Black Sea coast.
AtıfScopus10WoS13OpenAlex12İncele - MakaleYalnız künye2012Scopus SJRQ2Virtual point detector for HPGe detectors for 26.6-1332 keV photon energies by experiment and Monte Carlo simulation
Çelik, N.; Çevik, U.; Küçükömeroğlu, B.
Variation of virtual point detector (VPD) position inside HPGe detector as a function of source photon energy for the energy range from 26.6 to 1,332 keV was investigated. Although VPD concept was well established for HPGe detectors from 59.5 to 10 MeV, a new attempt was made to obtain VPD positions for photon energies below 59.5 keV. It was found that VPD position shows different functional behavior for the energy ranges 26.6-59.5 keV and 59.5-1,332 keV. The VPD position decreases with increasing energy for 26.6, 31.7, 36.4, and 37.3 keV and increases with the energy until it reaches a plateau. The functional behavior of VPD position for the energy range 26.6-59.5 keV was attributed to the dead layer thickness of the Ge crystal. Monte Carlo simulations were performed to investigate the behavior of VPD position with various dead layer thickness ranging from 100 to 800 μm. It was seen that VPD position increases with increasing energy for 31.7, 59.5, and 80.1 keV more significant at relatively lower energies, but constant for the energies 661-1,332 keV.
AtıfScopus4WoS3OpenAlex3İncele