Yayınlar
Koleksiyondaki öğeler
- MakaleYalnız künye2015Scopus SJRQ2Evaluation of cadastre renovation studies in Turkey
Döner, F.
In Turkey, cadastral surveys have been carried out by various measurement techniques, at different standards and based on different legislation. Consequently, one of the most important problems with the cadastre is that approximately half of the current cadastral maps are insufficient to meet the expectations of today’s modern cadastre. In order to resolve the problem and renew the cadastral maps, the General Directorate of Land Registry and Cadastre commenced the Land Registry and Cadastre Modernization Project in 2009. Within the scope of the project, it is intended that 10 million parcels will be renewed by the end of 2014. This study aims to evaluate the cadastre renovation studies in Turkey with respect to their legal and technical aspects using a case study area. Results show that cadastre renovation studies may be insufficient to enrich and update the cadastral data. As a solution, legal amendments should be made in the Cadastre Law in a manner that will allow a new cadastral survey to be performed.
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İncele - MakaleYalnız künye2015Scopus SJRQ1Effect of applications of organic solid cattle manure on Hungarian vetch and barley intercropping mixtures grown on soils of different depths
Yolcu, H.
Sloping fields on soils of shallow depth to tillage are commonly left uncultivated in many parts of the world. This study was conducted to compare the effects on morphological traits, dry-matter (DM) yield, legume ratio (LR), crude protein content (CP), crude protein yield (CP yield) and mineral concentrations (N, P, K, S, Ca, Cu, Fe, Mg, Mn, Na, B and Zn) of Hungarian vetch (Vicia pannonica Crantz.) and barley (Hordeum vulgare L.) grown in intercropping mixtures in response to three rates of organic solid cattle manure application (M0: 0, M1: 10, M2: 20 t ha-1). Experimentation was conducted on soils of two different soil depths [shallow (8-12 cm; low-medium erosion risk) and normal soil depth (18-22 cm; no erosion risk)] on a sloping field in the 2006-2007 and 2007-2008 growing seasons at Gumushane, Turkey. Herbage harvested on the shallow depth area had 22-73% less DM yield, 14-72% less CP yield, 6-9% greater CP content and generally higher minerals contents than herbage from the normal soil depth area. Cattle manure applications increased DM yield by about 23%, increased CP content and CP yield, and also increased the contents of most minerals in herbage of the intercropping mixtures, relative to the control, averaged over the two soil depths. It is suggested that, for areas with shallow soil depths that are prone to erosion, plant cover should be used for forage production, and that fertilization with solid cattle manure at 20 t ha-1 can support production of quality forage of acceptable DM yield.
AtıfScopus6WoS5OpenAlex4İncele - 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 - MakaleYalnız künye2013Scopus SJRQ1Post-collisional adakitic volcanism in the eastern part of the Sakarya Zone, Turkey: Evidence for slab and crustal melting
Dokuz, Abdurrahman; Uysal, Ibrahim; Siebel, Wolfgang; Turan, Mehmet; Duncan, Robert; Akçay, Miǧraç
New geochemical and isotopic data for post-collisional Early Eocene and Late Miocene adakitic rocks from the eastern part of the Sakarya Zone, Turkey, indicate that slab and lower crustal melting, respectively, played key roles in the petrogenesis of these rocks. The Early Eocene Yoncali{dotless}k dacite (54.4 Ma) exhibits high Sr/Y and La/Yb ratios, low Y and HREE concentrations, moderate Mg# (44-65), and relatively high εNd and low ISr values, similar to adakites formed by slab melting associated with subduction. Geochemical composition of the Yoncali{dotless}k dacite cannot be explained by simple crystal fractionation and/or crustal contamination of andesitic parent magma, but is consistent with the participation of different proportions of melts derived from subducted basalt and sediments. Sr/Y correlates horizontally with Rb/Y, and Pb/Nd correlates vertically with Nd isotopic composition, indicating that Sr and Pb budgets are strongly controlled by melt addition from the subducting slab, whereas positive correlations between Th/Nd and Pb/Nd, and Rb/Y and Nb/Y point to some contribution of sediment melt. In addition to low concentrations of heavy rare earth elements (~2-3 times chondrite), a systematic decrease in their concentrations and Nb/Ta ratios with increasing SiO2 contents suggests that slab partial melting occurred in the garnet stability field and that these elements were mobilized by fluid flux. These geochemical and isotopic signatures are best explained by slab breakoff and fusion shortly after the initiation of collision. Although the Late Micone Tavdaǧi{dotless} rhyolite (8.75 Ma) has some geochemical features identical to adakites, such as high Sr/Y and La/Yb ratios, low Y and HREE concentrations, other requirements, such as sodic andesite and/or dacite with relatively high MgO and Mg# (>50), relatively high Ni and Cr, low K2O/Na2O (<0.4), high Sr (>400 ppm), for slab-derived adakites are not provided. It is sodic in composition and shows no traces of fractionation from dacitic parent magma. Low Nd and high Sr isotope ratios suggest derivation by partial fusion of calc-alkaline, juvenile crust with high Sr/Y and La/Yb ratios.
AtıfScopus84WoS79OpenAlex76İncele - 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 - MakaleAçık Erişim2014Scopus SJRQ1Multiwalled CNT-pHEMA composite conduit for peripheral nerve repair
Arslantunali, D.; Budak, G.; Hasirci, V.
A nerve conduit is designed to improve peripheral nerve regeneration by providing guidance to the nerve cells. Conductivity of such guides is reported to enhance this process. In the current study, a nerve guide was constructed from poly(2-hydroxyethyl methacrylate) (pHEMA), which was loaded with multiwalled carbon nanotubes (mwCNT) to introduce conductivity. PHEMA hydrogels were designed to have a porous structure to facilitate the transportation of the compounds needed for cell nutrition and growth and also for waste removal. We showed that when loaded with relatively high concentrations of mwCNTs (6%, w/w in hydrogels), the pHEMA guide was more conductive and more hydrophobic than pristine pHEMA hydrogel. The mechanical properties of the composites were better when they carried mwCNT. Elastic modulus of 6% mwCNT loaded pHEMA was twofold higher (0.32 ± 0.06 MPa) and similar to that of the soft tissues. Electrical conductivity was significantly improved (11.4-fold) from 7 × 10-3 Ω-1.cm-1 (pHEMA) to 8.0 × 10-2 Ω-1.cm-1 (6% mwCNT loaded pHEMA). On application of electrical potential, the SHSY5Y neuroblastoma cells seeded on mwCNTs carrying pHEMA maintained their viability, whereas those on pure pHEMA could not, indicating that mwCNT helped conduct electricity and make them more suitable as nerve conduits.
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İncele - 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 künye2011Scopus SJRQ1Modeling and forecasting of Turkey's energy consumption using socio-economic and demographic variables
Kankal, Murat; Akpinar, Adem; Kömürcü, Murat Ihsan; Özşahin, Talat Şükrü
This study deals with the modeling of the energy consumption in Turkey in order to forecast future projections based on socio-economic and demographic variables (gross domestic product-GDP, population, import and export amounts, and employment) using artificial neural network (ANN) and regression analyses. For this purpose, four diverse models including different indicators were used in the analyses. As the result of the analyses, this research proposes Model 2 as a suitable ANN model (having four independent variables being GDP, population, the amount of import and export) to efficiently estimate the energy consumption for Turkey. The proposed model predicted the energy consumption better than the regression models and the other three ANN models. Thus, the future energy consumption of Turkey is calculated by means of this model under different scenarios. The predicted forecast results by ANN were compared with the official forecasts. Finally, it was concluded that all the scenarios that were analyzed gave lower estimates of the energy consumption than the MENR projections and these scenarios also showed that the future energy consumption of Turkey would vary between 117.0 and 175.4. Mtoe in 2014.
AtıfScopus233WoS199OpenAlex282İncele - MakaleYalnız künye2011Scopus SJRQ1Dynamic Characteristics of a Prototype Arch Dam
Sevim, B.; Bayraktar, A.; Altunışık, A.C.; Adanur, S.; Akköse, M.
This study determines the dynamic characteristics of a prototype arch dam-reservoir-foundation system using Operational Modal Analysis method. Achievement of this purpose involved construction of a prototype arch dam-reservoir-foundation system under laboratory conditions. Ambient vibration tests on the arch dam model identified its natural frequencies, mode shapes, and damping ratios. Natural excitations such as small impact loads vibrated to arch dam. Sensitivity accelerometers which were placed on the dam's crest collected signals in measurements. Measurements were recorded for empty and full reservoirs. Operational Modal Analysis software processed signals which were collected from the ambient vibration tests. Enhanced Frequency Domain Decomposition technique estimated dynamic characteristics of the dam. Results showed that there was an approximate 20-25% difference between natural frequencies related to empty and full reservoirs.
AtıfScopus9WoS9OpenAlex8İncele - MakaleYalnız künye2013Scopus SJRQ3Analytical approximate solutions of fractionel convection-diffusion equation with modified Riemann-Liouville derivative by means of fractional variational iteration method
Merdan, M.
In this article, an analytical approximate solution of nonlinear fractional convection-diffusion with modified Riemann-Liouville derivative was obtained with the help of fractional variational iteration method (FVIM). A new application of fractional variational iteration method (FVIM) was extended to derive analytical solutions in the form of a series for this equation. It is indicated that the solutions obtained by the FVIM are reliable and an effective method for strongly nonlinear partial equations with modified Riemann-Liouville derivative.
AtıfScopus15WoS15İncele - MakaleYalnız künye2015Scopus SJRQ1Assessment of metal pollution associated with an alteration area: Old Gümüşhane, NE Black Sea
Vural, Alaaddin
The objective of this study was to determine the potential environmental risks associated with the Kirkpavli (Old Gümüşhane in northern Turkey) alteration area by quantifying pollution in soil. The Kirkpavli (Old Gümüşhane) alteration area is situated at the south of the deposit with the same name of gold-silver-bearing lead, zinc, and copper in the southern part of the Black Sea Tectonic Unit (Eastern Pontides). In this study, 28 soil samples acquired from the alteration area were analyzed for contents of some main elements including lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), cobalt (Co), manganese (Mn), nickel (Ni), and arsenic (As). Contents of the elements in the area were determined, and high values were obtained such as 1,171 mg/kg for As, 12.4 mg/kg for Cd, 77.3 mg/kg for Co, 341 mg/kg for Cu, 1,172 mg/kg for Mn, 51.9 mg/kg for Ni, 3,725 mg/kg for Pb, and 880 mg/kg for Zn. Soil contamination was appraised on the basis of Geoaccumulation Index (Igeo), Enrichment Factor (EF), Pollution Index, and Integrated Pollution Index. The calculated results of Igeo, EF, and PI of the elements can be shown in descending order of parameters as As > Pb > Cd > Zn > Cu > Co > Mn. The parameters for some of these elements indicated extremely high contamination (Igeo > 5), extremely high enrichment (EF > 40), and high pollution (PI > 3). High Igeo, EF, and PI values of As, Pb, and Cd in the soil samples mean that soil pollution is typically associated with alteration area. Considering its location and the results of this study, the Kirkpavli alteration area is a significant source of pollution and may have ecotoxicological effects on terrestrial, groundwater, and aquatic ecosystems in the region.
AtıfScopus24WoS26OpenAlex30İncele - MakaleYalnız künye2013Scopus SJRQ3The relationship among the current deficit - Short term capital movements and economic growth: Evidence from Turkey
Akbas, Yusuf Ekrem; Senturk, Mehmet; Sancar, Canan; Akyazi, Haydar
In this study, it was analysed if there is a short and long term relationship among the current deficit, short-term capital movements and the economic growth within the periods of 1998Q1-2011Q4 in Turkey. It was used to Autoregressive Distributed Lag model for analyzing the series. As a result of the Autoregressive Distributed Lag model test, it was confirmed the co-integration relationship among the series related to current deficit, economic growth and short term capital flows in short term and long term.
- 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.
AtıfScopus5İncele - MakaleAçık Erişim2015Scopus SJRQ3Effects of Turkish propolis on expression of hOGG-1 and NEIL-1
Turan, İbrahim; Değer, Orhan; Aliyazicioğlu, Yüksel; Demir, Selim; Kilinç, Kağan; Sümer, Ayşegül
Background/aim: Propolis is a bee product with antioxidative, antimutagenic, and other beneficial properties, and it is used as a natural drug. It is rich in polyphenolic compounds. Its composition varies depending on the particular geographical region. Oxidative stress is caused by an imbalanced free radical production and antioxidant system. The effects of flavonoids on the expression of DNA repair enzymes have been examined previously; however, no study has investigated the effects of propolis. This study investigated the effects of ethanolic extracts of Turkish propolis (EEP) on the expression of DNA repair enzymes. Materials and methods: The effects of EEP and tertiary-butyl-hydroperoxide (t-BHP) on cell viability were determined using MTT. DNA damage was determined using comet assay. mRNA expression of target enzymes was detected using RT-PCR. Results: According to the cytotoxicity analysis, after a recovery time of 4 h, appropriate damage agent t-BHP and optimum EEP concentrations were 300 µM and 200 µg/mL, respectively. 8-Oxoguanine-glycosylase (hOGG-1) and endonuclease-VIII-like-1 (NEIL-1) expressions increased in the positive control group (t-BHP alone) and the study group (t-BHP+EEP). Maximum increase in NEIL-1 expression was at hour 12 in the positive control group and at hour 8 in the study group. Conclusion: EEP can be considered as a potential source of functional food and pharmaceutical agents.
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İncele - MakaleYalnız künye2015Scopus SJRQ1CFRP composite retrofitting effect on the dynamic characteristics of arch dams
Altunişik, Ahmet Can; Günaydin, Murat; Sevim, Bariş; Bayraktar, Alemdar; Adanur, Süleyman
The purpose of this study is to investigate the effect of retrofitting dynamic characteristics of a damaged laboratory arch dam model, subsequently repaired with high-strength structural mortar and strengthened with composite carbon fiber reinforced polymer. This study constructed in laboratory conditions is a prototype arch dam-reservoir-foundation model. Five test cases of ambient vibration on the arch dam model illustrate the changes in dynamic characteristics: natural frequency, mode shape, and damping ratio, before and after retrofitting. The ambient vibration tests collected data from the dam body during vibrations by natural excitations which provided small impacts and response signals from sensitivity accelerometers placed at crest points. Enhanced Frequency Domain Decomposition Method in the frequency domain extracts the experimental dynamic characteristics. At the end of the study, experimentally identified dynamic characteristics obtained from all test cases have been compared with each other. Apparently, after the retrofitting, the natural frequencies of the dam body increased considerably, demonstrating that the retrofitting, including repairing and strengthening is very effective on the flashback of initial dynamic characteristics.
AtıfScopus26WoS23OpenAlex21İncele - BildiriYalnız künye2014Note on small singular values of sequences of matrices
Ashyralyyev, Charyyar; Cakir, Zafer
In this paper, some sequences of matrices for matrix pencils are considered. Properties of small singular values of these matrices are investigated. Estimates for singular values are obtained. The result of computer calculations is given.
- Derleme MakaleYalnız künye2012Scopus SJRQ1Hydropower 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.
AtıfScopus51WoS43OpenAlex54İncele - BildiriYalnız künye2014Approximate solution of the two-dimensional singular integral equation
Ashyralyyev, Charyyar; Cakir, Zafer
Approximate quadrature formulas for the numerical calculation of the two-dimensional Vekua potential and singular integrals are obtained. The mechanical quadrature method for the two-dimensional quasilinear singular integral equation with Vekua operators is described. The numerical results are compared with the exact solution of the integral equation.
AtıfScopus2WoS3OpenAlex3İncele - MakaleYalnız künye2011Scopus SJRQ2Preconcentration of Cd(II) and Cu(II) ions by coprecipitation without any carrier element in some food and water samples
Duran, Celal; Ozdes, Duygu; Sahin, Deniz; Bulut, Volkan Numan; Gundogdu, Ali; Soylak, Mustafa
A simple, rapid, sensitive and environmentally friendly separation and preconcentration procedure, based on the carrier element free coprecipitation (CEFC) of Cu(II) and Cd(II) ions by using an organic coprecipitant, 2-{[4-(4-fluorophenyl)-5-sulphanyl-4H-1,2,4-triazol-3-yl]methyl}-4-{[(4-fluorophenyl) methylene]amino}-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (MEFMAT) was developed. The analyte ions were determined by flame atomic absorption spectrometric (FAAS) determinations. The optimum conditions for the coprecipitation process were investigated on several commonly tested experimental parameters such as pH of the solution, amount of MEFMAT, sample volume, standing time, centrifugation rate and time. The influences of some anions, cations and transition metals on the recoveries of analyte ions were also investigated, and no considerable interference was observed. The preconcentration factor was found to be 50. The detection limits for Cu(II) and Cd(II) ions based on the three times the standard deviation of the blanks (N:10) were found to be 1.49 and 0.45μgL-1, respectively. The relative standard deviations were found to be lower than 3.5% for both analyte ions. The method was validated by analyzing two certified reference materials (CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C) and spike tests. The procedure was successfully applied to sea water and stream water as liquid samples and tobacco, hazelnut and black tea as solid samples.
AtıfScopus56WoS54OpenAlex47İncele - BildiriYalnız künye2012Control of an optimum modelled air heating system and real time simulation
Özden, Talat; Tuǧal, Harun; Okumuş, Halil I.
In this paper, a controller was designed for air heating system and parameters of controller were calculated. A real time simulation of system was done to compare properties of controller both in simulation and real time simulation. To design a controller the system should be modelled. The modelling processes have done in our previous article was about modelling of air heating system.
AtıfScopus1OpenAlex1İncele
