Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Merdan, Mehmet(9)
- Yildirim, Ahmet(7)
- Gezen, Cem(5)
- Memetoglu, Mehmet Erdem(5)
- Oncel, Mustafa(5)
- Altuntas, Yunus E.(4)
- Duran, Celal(4)
- Kement, Metin(4)
- Kömürcü, Murat Ihsan(4)
- Okkabaz, Nuri(4)
- Vural, Selahattin(4)
- Akkan, Yasar(3)
- Akpinar, Adem(3)
- Aksakal, Nihat(3)
- Ashyralyyev, Charyyar(3)
- Ayaydin, Hasan(3)
- Cakir, Zafer(3)
- Can, İbrahim(3)
- Cihan, Hamit(3)
- Gökdogan, Ahmet(3)
- Gökdoǧan, Ahmet(3)
- Kalkan, Asim(3)
- Kaya, Elif Çelenk(3)
- Kaygusuz, Abdullah(3)
- Kuzudisli, Ali(3)
- Maden, Nafiz(3)
- Orhan, Salih(3)
- Sipahi, Ferkan(3)
- Ural, Dilek(3)
- Çatak, Adem(3)
- Adanur, Suleyman(2)
- Akbulut, O.(2)
- Akkan, Yaşar(2)
- Akpinar, A.(2)
- Aksakal, V.(2)
- Aksakal, Vecihi(2)
- Alemdag, Selcuk(2)
- Altunisik, Ahmet Can(2)
- Arslan, Mehmet(2)
- Ashyralyev, A(2)
Yayınlar
- MakaleYalnız künye2012A-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.
- MakaleYalnız künye2012Aspirin, 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.
- MakaleYalnız künye2012Synthesis 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.
- MakaleYalnız künye2012Yield 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.
- MakaleYalnız künye2012Chaotic 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.
- MakaleAçık Erişim2012Dehydrated 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.
- MakaleAçık Erişim2012Assessment 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.
- BildiriYalnız künye2012Using 3D models from multidetector computed tomography images for diagnostic of Hallux-valgus
Catal, Hatice; Corumluoglu, Ozsen
Medical image processing techniques is often used in medicine or some engineering fields. In this study, we used basic techniques of metric digital image processing. Axial MDCT (Multidetector Computed Tomography) Ballerina's feet images were used to form 3D models by 3D-Doctor software. The virtual 3D models are in high accuracy. Hallux-valgus angles were calculated and recorded by using these 3D virtual models. We hope that the results from the biometric and reconstructive techniques carried out in this work will contribute to the present knowledge in medicine especially on ballerina's foot health and digital image processing in this area.
- MakaleAçık Erişim2012The 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.
- MakaleYalnız künye2012Elemental 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.
- MakaleYalnız künye2012Performance 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.
- BildiriYalnız künye2012Finite difference method for the reverse parabolic problem with Neumann condition
Ashyralyyev, Charyyar; Dural, Ayfer; Sozen, Yasar; Ashyralyev, A; Lukashov, A
A finite difference method for the approximate solution of the reverse multidimensional parabolic differential equation with a multipoint boundary condition and Neumann condition is applied. Stability, almost coercive stability, and coercive stability estimates for the solution of the first and second orders of accuracy difference schemes are obtained. The theoretical statements are supported by the numerical example.
- MakaleYalnız künye2012A 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.
- BildiriYalnız künye2012Designing a load agent for power management with a multi-agent home automation system
Özden, Talat; Okumuş, Halil Ibrahim
In this study, a load agent design is performed for the power management which lets us use existing electrical energy for consumer's needs, comfort and criteria in the areas such as flats and commercial buildings that independently meet their energy need from renewable energy sources. The load agent is designed on the basis of radio-frequency communication so it is a wireless communication system which also has the ability of switching off or making power flow by measuring current of the load. The agent has a flexible structure in order to be compatible with all ambient equipments. It can work with all equipments on the system properly, without any hardware changing. And this is shown in the paper.
- MakaleAçık Erişim2012Determination 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.
- MakaleYalnız künye2012Artificial 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.
- MakaleAçık Erişim2012Numerical 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.
- MakaleYalnız künye2012The 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.
- Kitap BölümüYalnız künye2012Geophysical approach for the detection and evaluation of geothermal energy potential stimulated from geology and tectonics in Cappadocia region (central Turkey)
Maden, Nafiz
Geothermal energy, which is a renewable energy source, can be used to heat buildings or generate electricity and does not contribute to air pollution when used properly, and it is heat continuously produced inside the earth that generates geological phenomena on a planetary scale. Central Anatolia is a triangular region which is limited by North Anatolian Fault Zone (NAFZ) to the north, East Anatolian Fault Zone (EAFZ) to the east, Dead sea FZ and Cyprus FZ to the south. The tectonic structure of the Cappadocia region is composed of NW trending Salt Lake Fault Zone extending approximately 220 km in length, Salanda fault zone extending 140 km, and NE trending Central Anatolian Fault zone more than 700 km in length. There are 82 geothermal regions having 171 sources with low and high temperatures due to the young volcanism and tectonic activities in this region. These geothermal regions caused by fault and fracture zones extending to the mantle parallel to the tectonic zones of the region and are situated on the areas having low Curie, high heat flow values. The Curie point depth, heat flow and geothermal gradient values determined from geophysical data of the region are correlated with tectonics and geothermal potential of the region. While the minimum crustal thickness is 38 km, the maximum crustal thickness is 41 km in Mt. Hasan and Mt. Erciyes. The Curie point depth value is computed as 13.7 km determined from magnetic anomaly data of the region. The geothermal gradient and heat flow values are estimated to be 42.3 °Ckm-1 , 88.8 mWm-2 , respectively. Geothermal systems and reservoir temperature of geothermal sources should be understood clearly to provide sustainability of the project with respect to the economical conditions. Various geothermometers methods have been used to determine the reservoir temperature in order to estimate the field of usage of the thermal water before the drilling stage because of the high price of the borehole. Silica geothermometers method applied to the SiO2 content of the sources gives the best information about the reservoir temperature. The maximum temperatures and depth to reservoir of the geothermal sources located in the Kayseri region are estimated as 131.8 °C, 1.14 km, respectively, in Kayseri region. It is concluded from these values that the Cappadocia region has very high geothermal potential caused by tectonic activities after the Late Triassic and partial melting of the lower crust.
- Derleme MakaleYalnız künye2012Hydropower for sustainable energy development in Turkey: The small hydropower case of the Eastern Black Sea Region
Capik, Mehmet; Osman Ylmaz, Ali; Cavusoglu, Ibrahim
Turkey is a rich country from the point of variety and potential of renewable energy resources. Hydros, winds, biomass, solar and geothermal are important renewable and environmentally friendly sources for energy in Turkey. Turkey produces large amount of hydropower with a total gross hydropower potential of 433 TW h/yr, which is equal to 13.8% of the total hydropower potential of Europe. Technically useable potential is 216 TW h/yr and economic potential is 140 TW h/yr. The main aim of the present study is to investigate hydropower potential of Turkey and small hydropower plants in Eastern Black Sea Region for sustainable energy development in Turkey. The geography of Turkey especially, Eastern Black Sea Region supports and suitable the development of the small hydro plants to increase the energy generation and utilization of available water sources in Turkey. Besides, the paper deals with hydropower policies to meet ever increasing energy demand for sustainable development of Turkey.