Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleAçık Erişim2012
    Adaptive multi-step differential transformation method to solving nonlinear differential equations

    Gökdogan, Ahmet; Merdan, Mehmet; Yildirim, Ahmet

    In this paper, we propose a fast and effective adaptive algorithm for the multi-step differential transformation method (MsDTM). This approach named as the adaptive MsDTM is applied to a number of nonlinear differential equations and numerical results are given. At the same time, a comparison between the MsDTM and the adaptive MsDTM reveals that the proposed approach is an efficiency tool for solving the considered equations using fewer time steps. (C) 2011 Elsevier Ltd. All rights reserved.

  • MakaleYalnız künye2011
    Assessment of natural radioactivity and mass attenuation coefficients of brick and roofing tile used in Turkey

    Damla, N.; Cevik, U.; Kobya, A. I.; Celik, A.; Celik, N.; Yildirim, I.

    In this study the distribution of natural radionuclides ((226)Ra, (232)Th, (40)K) in brick and roofing tile samples commonly used as building materials in Turkey was measured by using gamma spectrometry. The activity concentrations, radium equivalent activities (Ra(eq)), representative level index, indoor absorbed dose rate in air values and annual effective dose due to the intake of the above-mentioned radionuclides in the brick and roofing tile samples were estimated to assess the radiation hazard for people living in dwellings made of the materials studied. The measured average activity concentrations of (226)Ra, (232)Th and (40)K were 34 +/- 14, 34 +/- 13 and 462 +/- 175 Bq.kg(-1), respectively, for brick samples. For roofing tile, the average activity concentrations of (226)Ra, (232)Th and (40)K were measured to be 34 +/- 14, 33 +/- 12 and 429 +/- 161 Bq.kg(-1), respectively. The concentrations for these natural radionuclides were compared with the reported data of other countries. The Ra(eq) values of all samples were lower than the limit of 370 Bq.kg(-1), equivalent to a gamma dose of 1.5 mSv.a(-1) recommended by OECD. This study shows that the measured brick and roofing tile samples do not pose any significant source of radiation hazard and are safe to be used as building materials. Moreover, the experimental mass attenuation coefficients (mu/rho) of brick and roofing tile samples were determined in the energy range 80-1332 keV using the gamma ray transmission method. The experimental mass attenuation coefficients were compared with theoretical values obtained using XCOM. It was found that the computed values and the experimental results of this work are in good agreement with those reported in the literature. The chemical compositions and structural analysis (XRD) of the brick and roofing tile samples are also presented. (C) 2011 Elsevier Ltd. All rights reserved.

  • MakaleYalnız künye2011
    Effects of backfill on seismic behavior of rectangular tanks

    Livaoglu, Ramazan; Cakir, Tufan; Dogangun, Adem; Aytekin, Mustafa

    The reliability and/or stability of the lifeline structures against failure under seismic loads are of critical concern, and must be studied carefully. Therefore, the main objective of this paper is to demonstrate the commonly encountered backfill effects on the dynamic response of rectangular tanks. However, only the exterior wall of the tank which interacts with both the backfill and fluid is tackled, as each part of the structure shows considerable differences in terms of both the load bearing mechanisms and the geometrical and positional differences. Finite element analyses are employed, taking into consideration the fluid-wall-backfill interaction. The analyses are conducted to observe whether or not both backfill and wall behavior can be affected by variation of the internal friction angle. For that purpose, some comparisons are made on vertical displacements of the backfill, roof displacements, stress responses, etc., by means of internal friction angle variations of the backfill from 25 degrees to 40 degrees. Consequently, it is observed that the variations on maximum vertical displacements are affected considerably. In contrast, the maximum stress responses are affected partially. However, the inertial effects of the backfill show that pseudo-static approximations may be insufficient to understand the dynamic behavior of the backfill-wall-fluid system. (C) 2011 Elsevier Ltd. All rights reserved.

  • Derleme MakaleYalnız künye2011
    Development of hydropower energy in Turkey: The case of Coruh river basin

    Akpinar, Adem; Kömürcü, Murat Ihsan; Kankal, Murat

    The main objective in doing the present study is to investigate the sustainable development of hydropower plants in the Coruh river basin of Turkey, which is least problem river of Turkey in respect to international cooperation as compared with Turkey's other trans-boundary waters. Initial studies concerning the hydropower production potential in Coruh basin had been carried out by Turkish authorities in the late 1960s. Total installed power capacity and annual average energy generation of 37 dams and run of river (without storage) hydropower plants developed at various project stages by The Electrical Power Resources Survey and Development Administration (EiE) in Coruh basin are 3132.70 MW and 10.55 TWh/yr, respectively. Today, this generation value corresponds 6.45% of Turkey's energy consumption in 2006 while it meets 6.3% of total electricity energy production of Turkey which is equal to 167.9 TINh/yr in 2006. Besides, this potential developed at various project stages in Coruh basin will provide 24.1% of Turkey's hydroelectric energy generation being equal to 43.8 TWh/yr in 2006. (C) 2010 Elsevier Ltd. All rights reserved.

    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 13 · İklim Eylemi
  • MakaleYalnız künye2011
    Determination of proper peaking time for Ultra-LEGe detector

    Karabidak, S. M.; Kaya, S.; Çevik, U.; Çelik, A.

    Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the proper peaking time for particular detector systems is important. The characteristic X-rays emitted from pure some elements were detected by using an Ultra-LEGe detector connecting a Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by an HM 203-7 oscilloscope connecting amplifier. The proper peaking time for Ultra-LEGe is determined as 3.84 mu s. (C) 2011 Elsevier Ltd. All rights reserved.

  • MakaleAçık Erişim2011
    On the numerical solution of the model for HIV infection of CD4+ T cells

    Merdan, Mehmet; Gökdogan, Ahmet; Yildirim, Ahmet

    In this article, a variational iteration method (VIM) is performed to give approximate and analytical solutions of nonlinear ordinary differential equation systems such as a model for HIV infection of CD4(+) T cells. A modified VIM (MVIM), based on the use of Fade approximants is proposed. Some plots are presented to show the reliability and simplicity of the methods. (C) 2011 Elsevier Ltd. All rights reserved.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleAçık Erişim2011
    Solving a fractional order model of HIV infection of CD4+ T cells

    Gokdogan, Ahmet; Yildirim, Ahmet; Merdan, Mehmet

    In this paper, a multi-step differential transform method (MsDTM) is performed to give approximate and analytical solutions of nonlinear fractional order ordinary differential equation systems such as a model for HIV infection of CD4+ T cells. The numerical solutions obtained from the proposed method indicate that the approach is easy to implement and accurate when applied to systems of fractional differential equations. Some figures are presented to show the reliability and simplicity of the methods.

  • MakaleYalnız künye2011
    Late Triassic subduction-related ultramafic-mafic magmatism in the Amasya region (eastern Pontides, N. Turkey): Implications for the ophiolite conundrum in Eastern Mediterranean

    Eyuboglu, Yener; Santosh, M.; Bektas, Osman; Chung, Sun-Lin

    The eastern Pontides orogenic belt of northeastern Turkey offers critical clues on convergent margin tectonics associated with the late Mesozoic-early Cenozoic geodynamic evolution of the eastern Mediterranean region. Here we report the geology, petrology, geochemistry, Nd-Sr-Pb isotopes and U-Pb zircon ages from a ultramafic-mafic complex in Aksalur which forms part of a series of Alaskan-type ultramafic-mafic bodies in the Amasya region located at the south-western corner of the eastern Pontides orogenic belt. These ultramafic-mafic intrusions occur as minor (30-300m in diameter), scattered, roughly circular bodies within the low-grade metamorphic rocks of the Tokat metamorphic massif. Petrographic studies characterise the rock types as gabbro and wehrlite, with the latter showing typical cumulate texture and mainly comprising serpentinized olivine, clinopyroxene, hornblende, mica and opaque minerals. The gabbroic rocks are characterized by relatively high initial ratios of 143Nd/144Nd (0.512618-0.512633) and low initial ratios of 87Sr/86Sr (0.70420-0.70435). Their initial Pb isotope ratios range from 17.306 to 17.771. The gabbros and cumulate wehrlites display geochemical distribution patterns analogous to the Alaskan-type intrusions that were derived from a subduction-related, high-alumina, hydrous basaltic parental magma in a convergent plate setting. LA-ICPMS analyses of zircons separated from the gabbros show high Th/U ratios (1.35-5.26) typical of magmatic origin. The U-Pb isotopic data define a weighted mean 206Pb/238U age of 203.3±4.9Ma. Detailed evaluation of the magma tectonics suggests that the Alaskan-type Aksalur ultramafic-mafic intrusions were accumulated in magma chamber(s) located at relatively shallow crustal levels. Two distinct magmatic pulses are identified: the first phase produced the gabbroic intrusions and the second phase was characterized by numerous small-scale werhlitic cumulate intrusions. In contrast to the previous models which assigned a mid-oceanic ridge-derived ophiolite affinity for ultramafic-mafic complexes in the eastern Pontides orogenic belt, our study reveals that these intrusions were derived from subduction-related high-alumina hydrous basaltic magmas transferred into the overlying relatively thin continental crust along deep-seated fractures.

  • MakaleAçık Erişim2011
    In vitro inhibition of α-carbonic anhydrase isozymes by some phenolic compounds

    Öztürk Sarikaya, Sevim Beyza; Topal, Fevzi; Şentürk, Murat; Gülin, Ihami; Supuran, Claudiu T.

    Carbonic anhydrase inhibitors (CAIs) are a class of pharmaceuticals used as antiglaucoma agents, diuretics, antiepileptics, in the management of mountain sickness, gastric and duodenal ulcers, neurological disorders or osteoporosis. We report here the inhibitory capacities of some phenolic compounds against three human CA isozymes (hCA I, hCA II, and hCA VI) and the gill carbonic anhydrase of the teleost fish Dicentrarchus labrax (European seabass) (dCA). The isozymes showed quite diverse inhibition profiles with these compounds. These data may lead to design novel CAIs with a diverse inhibition mechanism compared to sulfonamide/sulfamate inhibitors.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
  • MakaleYalnız künye2011
    Restructuring of Turkey's electricity market and the share of hydropower energy: The case of the Eastern Black Sea Basin

    Uzlu, Ergun; Akpinar, Adem; Kömürcü, Murat Ihsan

    This paper presents the historical development of Turkey's electricity power sector, the efforts for introducing competition in the power industry in Turkey, and the concerns regarding restructuring in Turkey. The contribution of the hydropower energy potential in Turkey to the reconstruction of the electricity structure in Turkey is also investigated. Then, among the 25 hydrological basins in Turkey, the Eastern Black Sea Basin located in the northeast of Turkey, which has great advantages from the view point of small hydropower potential or hydropower potential without storage, is chosen as the case study to carry out some investigations concerning its potential and to analyze the contribution of the private sector (the corporate body) in regard to the development of hydro potential in this basin within the scope of the 4628 Electricity Market Law. With this law, concerning the restructuring of the electricity market, private sector investments in this segment have increased. In total, 1524 hydroelectric power projects with 22 360 MW installed capacity has been implemented until January 22nd, 2009 and this figure is continuously rising.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
  • MakaleYalnız künye2011
    Migrating magmatism in a continental arc: Geodynamics of the Eastern Mediterranean revisited

    Eyuboglu, Yener; Santosh, M.; Dudas, Francis O.; Chung, Sun-Lin; Akaryali, Enver

    The eastern Pontide orogenic belt in Turkey offers a critical region to evaluate the geodynamic evolution of the eastern Mediterranean region during the late Mesozoic-Cenozoic. Here we synthesize results from our exhaustive database on the geochemical characteristics of adakitic magmatism from 137 bodies covering 7 domains in the southern zone of eastern Pontides. Together with new Pb-Sr-Nd results, we show that the adakitic magmatism in the eastern Pontide belt is clearly linked to slab window processes during ridge subduction, as against the earlier models that assumed partial melting of a delaminated or thickened lower continental crust following collision. The isotopic compositions display a complex pattern and suggest mixing of multiple source materials such as depleted mantle, enriched lithospheric mantle, and upper crust. We also confirm a southward polarity of subduction as against the previous models that assumed a northward subduction. We supplement our model with evidence for a northward propagation of the adakitic magmatism, spatial and temporal variations in arc magmatism, presence of south-dipping reverse faults and a synthesis of the available paleomagnetic data. Our studies also suggest that the Black-Sea is a remnant of the Tethyan ocean that was situated to the north of the arc during the late Mesozoic-Cenozoic as against the correlation to a late Mesozoic-Cenozoic back-arc basin related to a northward subduction of the Paleo- or Neo-tethyan oceanic lithosphere in alternate models. (C) 2010 Elsevier Ltd. All rights reserved.

  • MakaleYalnız künye2010
    Exergetic performance analysis of a recirculating aquaculture system

    Kucuk, Haydar; Midilli, Adnan; Özdemir, Atilla; Çakmak, Eyüp; Dincer, Ibrahim

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period.

    • SDG 2 · Açlığa Son
    • SDG 6 · Temiz Su ve Sanitasyon
    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 12 · Sorumlu Üretim ve Tüketim
  • BildiriYalnız künye2009
    Mineralogy and geochemistry of dacitic rocks accompanying the Murgul (Artvin, NE Turkey) massive sulfide deposit

    Sipahi, Ferkan; Sen, Cueneyt; Sadiklar, M. Burhan; Demir, Yilmaz

  • BildiriYalnız künye2009
    Alteration of Late Cretaceous dacites in the Murgul Area (Artvin, KD Turkey)

    Sipahi, Ferkan; Sadiklar, M. Burhan; Sen, Cueneyt; Demir, Yilmaz

  • MakaleYalnız künye2009
    Lithostratigraphy, facies, and deposition environment of the lower Jurassic Ammonitico Rosso type sediments (ARTS) in the Gümüşhane area, NE Turkey: Implications for the opening of the northern branch of the Neo-Tethys Ocean

    Kandemir, Raif; Yilmaz, Cemil

    Ammonitico Rosso type sediments (ARTS) form the bottom level of the Şenköy Formation in the Gümüşhane area. The formation accumulated in the rift-related basins triggered by extensional tectonic regimes in the Early Jurassic times. Six different sections were studied in this area in order to interpret the lithostratigraphy, facies, and deposition environments of the ARTS. Two basic lithofacies were distinguished, nodular-marly and nodular-calcareous. These facies provide useful information regarding depositional conditions in the area and environmental energy. These factors were mainly related to the relative sea-level that in turn was controlled by tectonic and eustasy conditions. In addition, seven different types of microfacies were recognized and described as a result of the detailed analysis of the sections. The results of the analysis show that these sediments in the Gümüşhane area were developed in transgressive phases/events. These sediments share characteristics with other peri-Mediterranean regions and sea-level curves, and show a similarity to the major transgressive pulse during the Pliensbachian stage. Deposition of ARTS was controlled by syn-depositional extensional movements, leading to their accumulation on top of tilted blocks, slopes and horsts in an open marine environment. The ARTS were developed during the rifting of the continental margins pointing up the phases of the Tethys opening. Neptunian dykes verifying this opening developed at different levels of the ARTS and were filled with overlying sediments. These results support the hypothesis that the ARTS were formed in tectonically active environments where extensional tectonic movements were continuously improved during the deposition of the ARTS.

  • Derleme MakaleYalnız künye2008
    Global warming and renewable energy sources for sustainable development: A case study in Turkey

    Bilgen, Selcuk; Keles, Sedat; Kaygusuz, Abdullah; Sari, Ahmet; Kaygusuz, Kamil

    Renewable energy sources have been important for humans since the beginning of civilization. For centuries and in many ways, biomass has been used for heating and cooking. Many centuries ago mankind was already utilizing the clearly visible power of water for mechanical drive purposes, as was also the case with wind. On the other hand, Turkey, with its young population and growing energy demand per person, its fast growing urbanization, and its economic development, has been one of the fast growing power markets of the world for the last two decades. It is expected that the demand for electric energy in Turkey will be 300 billion kWh by the year 2010 and 580 billion kWh by the year 2020. Turkey is heavily dependent on expensive imported energy resources that place a big burden on the economy and air pollution is becoming a great environmental concern in the country. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. This article presents a review of the potential and utilization of the renewable energy sources in Turkey. (c) 2006 Elsevier Ltd. All rights reserved.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 13 · İklim Eylemi
  • BildiriYalnız künye2007
    Environmental pollution originated from open dumping of solid waste in the cities of Eastern Black Sea

    Ersoy, H.; Ersoy, A. Firat; Dag, S.; Berkün, M.

  • MakaleYalnız künye2006
    Traditional wooden buildings and their damages during earthquakes in Turkey

    Doǧangün, Adem; Tuluk, Ö.Iskender; Livaoǧlu, Ramazan; Acar, Ramazan

    Wood is one of the oldest structural materials used in structures in many parts of the World. Woodframe buildings were also commonly constructed in Turkey until approximately 1960. After that, as reinforced concrete and masonry buildings have been preferred, wooden buildings have almost been forgotten. But, in 1999, Kocaeli and Duzce earthquakes reminded traditional buildings. Since reinforced concrete buildings presented high level of damage and traditional buildings relatively performed well during these earthquakes. In this study, types of traditional wooden buildings used in Turkey are mainly introduced and their damages in earthquakes are discussed. Damaged and undamaged wooden building photos are illustrated. Some structural weaknesses are highlighted by the earthquake damages including cracking and falling of plaster, failure of mortar, loosening or failing of connections, large lateral displacements, dislodgement of the masonry infill, loosening or failing of connections and failure of connections to foundation.

  • MakaleYalnız künye2006
    Mineralogy, petrography and whole-rock geochemistry of the Tertiary granitic intrusions in the Eastern Pontides, Turkey

    Arslan, M.; Aslan, Z.

    Granitic intrusions in Eocene and post-Eocene volcanic rocks outcrop in the Northern and Southern Zones of the Eastern Pontides, NE Turkey. Intrusions in the Northern Zone extend NW-SE whereas those in the Southern Zone are nearly E-W orientated. The contacts of the intrusions with the volcanic rocks are sharp, epidotized and include volcanic xenoliths. The margins of Southern Zone intrusions often contain abundant angular mafic microgranular enclaves of diorite to quartz diorite composition. The rocks also show evidence of mingling and mixing between coeval mafic and felsic magmas. Field observations suggest a stopping type of ascent and emplacement style for the intrusions. Petrographically, intrusions show variations in both colour and mineralogy with fine to medium granular, monzonitic, poikilitic, rapakivi, anti-rapakivi and graphic textures. Based on modal mineralogy, the Northern rocks are monzonite, quartz monzonite, monzodiorite and quartz monzodiorite whereas the Southern samples are monzogranite and granodiorite. The rocks are generally calc-alkaline to mildly alkaline transitional and metaluminous, and show a CAFEMIC trend. The Northern Zone intrusions form a post-collisional, A-type, alkaline monzonitic association and Southern Zone intrusions form a post-collisional, I-type, granodioritic calc-alkaline-transitional association. Whole-rock compositional data indicate that differentiation occurred via fractional crystallisation with or without magma mixing. Incompatible and rare earth element patterns indicate that both the Northern and the Southern Zone intrusions were derived from melting of a mantle region enriched by subduction-related fluids but evolved differently during ascent and emplacement. U-Pb zircon dating in the Southern Zone yields an intrusion age of 44.4±0.3 Ma. Regional geodynamics indicates post-collisional extensional tectonics in the region. Crustal involvement and the level of emplacement may have been important for magmatic evolution, especially for the Southern Zone intrusions, after the cessation of subduction and subsequent crustal thickening.

  • BildiriYalnız künye2005
    Hornblende and phlogopite-bearing ultramafic cumulates: Evidence for subduction-related ultramafic magmatism in the Eastern Pontides, Amasya area, NE Turkey

    Eyuboglu, Y; Bektas, O; Sen, C