Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(67)
- Merdan, Mehmet(59)
- Duran, Celal(49)
- Ozdes, Duygu(46)
- Kaygusuz, Abdullah(45)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Karsli, Orhan(36)
- Öztürk, Serkan(35)
- Dokuz, Abdurrahman(34)
- Araz, Onur(32)
- Kandemir, Raif(31)
- Kulakaç, Nurşen(29)
- Sipahi, Ferkan(29)
- Arslan, Mehmet(27)
- Baltaci, Cemalettin(27)
- Baltacı, Cemalettin(27)
- Kurt, Kemal(27)
- Topal, Fevzi(27)
- Gücer, Mehmet Ali(25)
- Peker, Iskender(25)
- Aydin, Faruk(24)
- Bayrakdaroglu, Serdar(24)
- Maden, Nafiz(24)
- Ozturk, Samet(24)
- Vural, Alaaddin(24)
- Yolcu, Halil(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Kankal, Murat(23)
- Reis, Hatice Catal(23)
- Ürkek, Bayram(23)
- Günen, Mehmet Akif(22)
- Kurnaz, Muammer(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(21)
- Ashyralyyev, Charyyar(20)
- Aydin, Aydanur(20)
- Bayraktar, Alemdar(20)
Yayınlar
- MakaleYalnız künye2011Scopus SJRQ3The Creative Destruction of Economic Development: The Schumpeterian Entrepreneuer
Basilgan, Muslum
The subject of the entrepreneur in economic theory has mostly been examined in terms of development. Schumpeter, who argued that the neoclassical economic theory could not explain the powers of the economic change due to its static base, took a different position by arguing the necessity of a dynamic theory. Schumpeter identified the entrepreneur as essential element of the dynamic theory of economic change. To Schumpeter, the major role of the entrepreneur is to realize new combinations or innovations that ensure economic change. The primary objective of this study is to explore the individual (psychological) and leadership (sociological) characteristics of the Schumpeterian entrepreneur, who leads to creative destruction via the new combinations in the capitalist system: to put forth his difference from other economic actors and to demonstrate his role in the future (the collapse) of capitalism.
AtıfTR Dizin6
İncele - MakaleAçık Erişim2011Scopus SJRQ3Breast Conserving Surgery and Modified Radical Mastectomy in Turkish Women with Breast Cancer: A Prospective Analysis of Quality of Life
Kement, Metin; Gezen, Cem; Asik, Ayla; Karaöz, Alev; Ustaalioglu, Basak Oven; Bilici, Ahmet; Öncel, Mustafa
Objective: The aim of this study is to compare the postoperative quality of life of the patients who underwent breast conserving surgery followed by radiotherapy (BCT) and the patients who underwent modified radical mastectomy (MRM) in our clinic. Material and Methods: The patients who were operated on with diagnosis of breast cancer in our clinic between January 2006 and January 2008 were included in the study. Those who received neoadjuvant therapy and who required radiotherapy after modified radical mastectomy and those in ASA classes 3 and 4 were excluded. The patients who were treated with modified radical mastectomy were included in the first group (Group MRM) and the patients who were treated with breast conserving therapy and radiotherapy thereafter were included in the second group (Group BCT). Quality of life of the patients were assessed using Medical Outcome Syudy-Short Form 36 (MOS SF-36) form six months after their treatment (surgery, radiotherapy, chemotherapy) was completed. Results: There were no significant differences between two groups in terms of age, evaluated socioeconomic parameters (education, income, marital status) and clinical parameters (stage, complications, adjuvant chemotherapy). Quality of life of the patients who underwent BCT (n=27) was worse than that of general Turkish population in six of eight (except vitality and social function) SF-36 scale and worse than mean values of normal individuals in NSABP BCPT trial in seven of eight (except vitality) scales. Besides, while physical component score was worse than that of general population (45.3 vs 52.6), mental component score (MCS) was relatively similar to general population (53.4 vs 51.7). When quality of life of the patients who underwent MRM (n=23) and BCT were compared, mean values of BCT group were found to be better in all scales and the difference was found to be statistically significant in six out of eight (except vitality and social function) scales (p<0.05). Conclusion: It can be stated that quality of life of the patient who underwent BCT due to breast cancer is impaired in terms of physical status, however did not change in terms of mental status. It can also be stated that quality of life of the patients who underwent breast conserving therapy were better than the ones who underwent modified radical mastectomy in terms of both physical and mental status.
AtıfWoS2OpenAlex4İncele - MakaleYalnız künye2011Scopus SJRQ1Effects 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.
AtıfWoS25OpenAlex23İncele - MakaleAçık Erişim2011A Different Cause of Trauma: Injury by a Mole Gun
Türkmen, Suha; Aktas, Aydin; Karaca, Yunus; Türedi, Suleyman; Gündüz, Abdulkadir
Although injuries caused by the home-made weapons such as mole guns, which are intended to fight off moles, are rare in Turkey they do still happen. They generally involve minor accidents and cause simple injuries to the hand. In this case we present a patient who involves a trauma to the left hand with fragmental fracture of the first metacarpal caused while checking whether a mole gun had fired or not. This injury is an example of an accident related to primitive, home- made weapons, used particularly in rural areas.
- Derleme MakaleYalnız künye2011Scopus SJRQ1Development 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.
AtıfWoS40OpenAlex54İncele - MakaleYalnız künye2011Scopus SJRQ1Determination 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.
AtıfWoS6OpenAlex9İncele - MakaleAçık Erişim2011Scopus SJRQ1On 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.
AtıfWoS66OpenAlex91İncele - MakaleYalnız künye2011Scopus SJRQ2Vibration-based operational modal analysis of the mikron historic arch bridge after restoration
Altunişika, Ahmet Can; Bayraktar, Alemdar; Sevima, Bariş; Birincia, Fatma
This research presents finite element modelling, vibration-based operational modal analysis, and finite element model updating of a restored historic arch bridge. Mikron historic bridge, constructed on Fi{dotless}rti{dotless}na River in Rize, Turkey, is the subject of this case study. The General Directorate for Highways of Turkey repaired the bridge's main structural elements, arches, sidewalls, and filler material in 1998. To construct a 3D finite element model of the bridge, ANSYS finite element software estimated the analytical dynamic characteristics. Induced ambient vibrations such as human walking and wind excited the model bridge to allow measurement of the bridge's responses. Enhanced frequency domain decomposition in frequency domain and stochastic subspace identification in time domain methodologies extracted experimental dynamic characteristics. A comparison of the analytical and experimental results showed significant agreement between mode shapes, but some differences in natural frequencies appeared. Consequently, updating the finite element model of the bridge by changing boundary conditions minimised the differences between analytical and experimental natural frequencies. After the finite element model updating process, the differences between natural frequencies declined from 7% to 2%.
AtıfScopus20WoS20OpenAlex21
İncele - MakaleAçık Erişim2011Scopus SJRQ3Bay laurel (Laurus nobilis L.) in Japanese quails feeding 1. Performance and egg quality parameters
Karaalp, Musa; Elmasta, Mahfuz; Genc, Nusret; Sezer, Metin; Yavuz, Musa; Ozkan, Mehmet
The aim of this study was to evaluate the effect of supplemented bay laurel (Laurus nobilis L.) leaves to a conventional diet of laying Japanese quail on the performance and some egg quality. A total number of 60 and 54 days old laying type quails were distributed into individual cages for three different treatments. The control diet did not containLaurus nobilis (LN) leaves (LNG) and the other diets were supplemented with 2 g (LN2) and 4 g (LN4) leaves kg-1, respectively. The trial lasted for a total of 10 weeks. Supplemented leaves of LN (2 or 4 g kg-1 feed) had no effect on any performance parameters, external and internal egg quality traits of quails. The diets have not changed the amount of egg yolk total cholesterol at 121 days old. However, egg yolk triglyceride concentration of quails fed LN4 diet was lower (p<0.01) than quails fed with the other diets at 121 days old. Besides, the amount of total cholesterol and triglyceride of egg yolk increased (p<O.01) in all of the groups with age. In egg yolk in the group receiving diet LN4, the level of palmitic acid was lower (p<0.05) and oleic acid was higher (p<0.05) than those of the other 2 groups at 118 days. Besides at that age, the level of pahnitic acid was lower and oleic acid was >55, 76 and 97 days. There was no change in the other fatty acids. The changes in total saturated and total monounsaturated fatty acids were parallel with palmitic acid and oleic acid, respectively. Total polyunsaturated fatty acid content in the present study did not change with diet and age. The results of this study demonstrated that supplemented a conventional diet with LN could change some biochemical parameters of quail egg yolk.
AtıfScopus14WoS9OpenAlex15İncele - MakaleYalnız künye2011Scopus SJRQ4New data on the harvestmen (Arachnida, Opiliones) fauna of Turkey
Kurt, Kemal; Snegovaya, Nataly Yu.; Demir, Hakan; Seyyar, Osman
A new collection of 8 species of harvestmen are reported from Turkey. Two of them: Zachaeus redikorzevi (Starega et Chevrizov, 1978) and Opilio coxipunctus (Sørensen, 1912), collected from the southern part of the country, represent new records for Turkish harvestmen fauna. These species are illustrated and their data regarding collecting sites and distribution all over the world are given.
AtıfScopus6WoS7İncele - MakaleYalnız künye2011Scopus SJRQ2A new Early Jurassic brachiopod fauna from the Eastern Pontides (Turkey)
Vörös, Attila; Kandemir, Raif
A newly collected Early Jurassic brachiopod fauna from the Kocamantaşi section (Gümüşhane region, Eastern Pontides, Turkey) yielded 160 specimens and 13 species (4 rhynchonellids, 3 spirifennids, 6 terebratulids). Apart from some long-ranging forms, five species prove the Late Pliensbachian age of the fauna. The paleoenvironmental setting of the Kocamantaşi fauna shows analogies to the Alpine Hierlatz limestones. On the basis of common lithological characters, bedding features and sedimentary associations, this lithofacies is interpreted as a complex of submarine, biodetrital talus associated with fault-related submarine rocky slopes. The numerical comparison of the Kocamantaşi brachiopod fauna to Pliensbachian brachiopod faunas of Europe revealed that the faunal similarity was the highest to Kotel (Balkans) and the Crimea. Very strong affinity was recorded to further NW-European faunas, whereas very low, or no similarity was recognized to the Mediterranean faunas. This paleobiogeographical result supports the hypothesis that in the Late Pliensbachian the Eastern Pontide segment of the Cimmerian microcontinent was far from the Gondwana and close to the Eurasian margin of the Tethys.
AtıfScopus18WoS17OpenAlex14İncele - MakaleYalnız künye2011Scopus SJRQ3Mineralogy and whole rock geochemistry of lzate Cretaceous sandstones from the eastern Pontides (NE Turkey)
Eker, Cigdem Saydam; Korkmaz, Sadettin
This study focuses on Upper Cretaceous sandstones of the Eastern Pontides to identify the source area, subaerial weathering level, and tectonic environment. Thirty four sandstone samples from six stratigraphic sections were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MC) and by petrographic investigation. The late Cretaceous sandstones are defined as lithic arenites and feldspathic wackes, and lithic wackes depending on mineralogical and matrix content. The sandstones have low to moderate SiO2 contents (25-59%; on average -56%). There are high positive correlations between SiO2 Al2O3, and TiO2 and negative correlations between SiO2 and K2O. Geochemically, the sandstones are classified mainly as grey wackes and lithic arenites. Chemical index of alteration (CIA) and chemical index of weathering (CIW) values for Upper Cretaceous sandstones vary from 19 to 48 % and 20 to 49 % respectively. The combination of CIW/CIA values suggests little transportation until final deposition. The ratios of Th/Sc (on average -0.42), La/Sc (-1.81), Co/Th (-5.05) and Zr/Hf (-39.1) of sandstone samples in the study area indicate a mafic source. Furthermore, high light rare earth elements (LREE)/heavy rare earth elements (HREE) ratios (on average -19.72) and negative Eu anomalies (except in the Dagbasi section) suggest a contribution from a felsic source. The lower trace element contents of the Upper Cretaceous sandstones in relation to the Post-Archean Australian Shale (PAAS), which are considered to be representative of the upper continental crust, show that the recycling processes in their source areas were probably less intense than those of the PAAS. SiGyAlA (3.2-7.9) and K2O/Na20 (0.3-1) ratios, together with the Th (on average -3.3 ppm), Zr (on average -91.9 ppm), Co (on average -15 ppm), and Sc (on average -12.6 ppm) contents of the late Cretaceous sandstones of the eastern Pontides indicate a magmatic arc origin. Sandstones of the Trabzon region were probably deposited in fore-arc basins, and those from the Gumushane and Giresun regions in back-arc basins.
AtıfScopus39WoS42OpenAlex39İncele - MakaleYalnız künye2011Scopus SJRQ2Radiological characterisation of Artvin and Ardahan provinces of Turkey
Kucukomeroglu, B.; Yesilbag, Y.O.; Kurnaz, A.; Celik, N.; Cevik, U.; Celebi, N.
Indoor radon concentration measurements were carried out and corresponding annual effective doses due to exposure to indoor radon were determined in Artvin and Ardahan provinces located in the eastern part of Turkey. The measurements were performed for four seasons in order to determine the seasonal fluctuations mostly observed in indoor environments. Indoor radon concentration values were observed to range from 21 to 321 Bq m-3 for the Artvin province and from 53 to 736 Bq m-3 for the Ardahan province. It was observed that minimum indoor radon concentration values were obtained in summer, while the highest ones were observed in winter. Indoor radon concentration values of the current study were compared with those of other provinces in Turkey. As elevated indoor radon concentrations are mostly correlated with high 238U activity concentrations in soil, a total of 57 and 33 soil samples were collected from the Artvin and Ardahan provinces, respectively, to determine 238U activity concentration as well as the concentration of 232TH and 40K-naturally occurring radionuclides. It was also observed that soil samples collected from the study areas contained 137Cs as an artificial radionuclide.
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İncele - MakaleYalnız künye2011Scopus SJRQ3Estimation of the carbon to nitrogen (C:N) ratio in compostable solid waste using artificial neural networks
Bayram, Adem; Kankal, Murat; Ozsahin, Talat Sukru; Saka, Fatih
Organic waste constitutes a majority of all municipal solid waste (MSW), a fact which yields some unfavorable results at open dumps, sanitary landfills, and incineration plants. As part of an integrated solid waste management strategy, composting could be applied to mixed collected MSWs or separately collected leaves, food, and yard wastes. The factor most crucial to successful composting is the carbon to nitrogen (C:N) ratio of the waste. This study employs two predictive models to estimate the C:N ratio of compostable MSW, an artificial neural network (ANN) and multiple linear regression (MLR). These models are based on 52 solid waste samples taken from the MSW open dumping area in Gümüşhane Province, Turkey. To estimate the C:N ratio, seven predictive variables were adopted. The proportions of food and yard (F&Y), and ash and scoria (A&S) waste; the moisture content (MC), the fixed carbon (FC) content, the total amount of organic matter (TOM), high calorific value (HCV), and pH. Fortytwo of the samples were used for training, and the remaining ten were used to test the models. The average relative error attained by the best ANN was 6.376%, while that attained by the MLR model was 11.002%. The effects of TOM content, F&Y percentage, and A&S percentage on the C:N ratio were investigated by running the ANN model for a range of input variables.
AtıfScopus7WoS6İncele - MakaleYalnız künye2011Scopus SJRQ1Crystal fractionation of adakitic magmas in the crust-mantle transition zone: Petrology, geochemistry and U-Pb zircon chronology of the Seme adakites, eastern Pontides, NE Turkey
Eyuboglu, Yener; Santosh, M.; Chung, Sun-Lin
Plutonic and porphyritic intrusions of adakitic rocks are widely distributed in the southern part of the eastern Pontides orogenic belt in Turkey. Ranging in age from late Paleocene to early Eocene, these intrusions provide critical information to evaluate the early Cenozoic geodynamic evolution of the eastern Mediterranean region. Here we report the results from our field, petrologic, geochemical and zircon U-Pb geochronological studies on adakitic intrusions in the Seme area from the southern part of eastern Pontides belt. The Seme granitoid, Daldibi dacite and Aslanca dacite porphyry from this region carry abundant plagioclcase, amphibole and biotite phenocrysts and have geochemical affinities typical of adakites including high SiO2 (58.48-75.6wt.%), Al2O3 (15.78-18.28wt.%), Na2O (3.94-5.08wt.%), Sr (506-1413ppm), and La (12.6-52.9ppm), moderate K2O (1.77-2.76wt.%), and low Y (4.7-14.2ppm) and Yb (0.28-1.29ppm). The early Eocene intrusions in the Seme area have compositional similarities with high-slica adakites, and their geochemical features suggest the involvement of slab-derived melts. The zircons separated from these rocks show euhedral crystal shapes with oscillatory cores typical of crystallization from magmas, as also confirmed by their high Th/U ratios (0.78 to 1.15). U-Pb analyses of zircons from the quartz diorite yielded a weighted mean 206Pb/238U age of 53.16±0.45Ma. Zircon grains from the Aslanca dacite porphyry occurring as a late phase within the Seme body show U-Pb isotopic ages of 53 and 52Ma concordant with U-Pb ages of zircons from quartz diorite. Based on major, trace and rare earth element data, we present a model suggesting crystal fractionation and/or differentation processes of subduction-related adakitic magmas stored in the crust-mantle transition zone, and their transfer into shallow depths of the overriding continental lithosphere.
AtıfScopus104WoS99OpenAlex100İncele - MakaleAçık Erişim2011Scopus SJRQ2Stability properties of certain durum wheat genotypes for major quality characteristics; [Makarnalik buĝday genotiplerinin temel kalite kriterleri bakimindan stabilite özellikleri]
Sakin, Mehmet Ali; Düzdemir, Oral; Sayaslan, Abdulvahit; Yüksel, Ferhat
Many ecological regions of Turkey are suitable for the production of durum wheat, and therefore the yield and quality of this wheat should be improved. In this study, stability properties associated with the pasta quality of 25 durum wheat (Triticum durum Desf.) genotypes grown in 3 dif erent locations (Tokat-Kazova, Diyarbaki{dotless}r, and Sivas-Ulaş) for 2 years (2005-2006, 2006-2007) were investigated. Durum wheat genotypes were composed of 12 registered varieties and 13 advanced experimental lines. Field trials were conducted in a randomized complete block design with 3 replications. Protein content, gluten index, sedimentation and specif c sedimentation volumes, yellow pigment content, and lipoxygenase activity of the durum wheats were measured as major quality characteristics. T e regression coef cient (bi) and mean square of deviation from regression (S2 d) were employed as the stability parameters. Genotypes, growing environments, and their interactions were found to be statistically signif cant (P < 0.01) for all investigated quality characteristics. No cultivars were determined to be simultaneously stable for all of the quality characteristics, yet some of the genotypes prevailed for certain quality characteristics. T e genotypes with the same origin took part in the same group as judged by the cluster analysis. Of the advanced experimental durum wheat lines, Line - 1, Line - 7, Line - 20, and Gdem - 12, which displayed better quality characteristics than the overall means, can be used as breeding materials. Of the registered varieties, Aydin - 93, Çeşit - 1252, and Gidara were determined to be stable by both parameters in certain quality characteristics.
AtıfScopus9WoS8İncele - MakaleYalnız künye2011Scopus SJRQ2Effects of random material and geometrical properties on structural safety of steel-concrete composite systems
Çavdar, Özlem; Bayraktar, Alemdar; Çavdar, Ahmet
A stochastic finite element-based algorithm for probabilistic analysis of structural systems made of composite sections with random material and geometrical properties under earthquake forces is proposed in this paper. Uncertainties in the structural parameters can be taken into account in this algorithm. For the perturbation-based stochastic finite element method, only the first two moments of random variables need to be known, and is numerically much more efficient and feasible than simulation techniques. The efficiency and accuracy of the proposed algorithm are validated by comparison with results of Monte Carlo simulation method. A summary of stiffness matrix formulation and perturbation-based stochastic finite element dynamic analysis formulation of structural systems made of composite sections is given. These are followed by suitable numerical examples, which indicate that employment of such a dynamic stochastic finite element method leads to significant economical, efficient and accurate solutions for the dynamic analysis of composite structures with stochastic parameters under earthquake forces.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2011Scopus SJRQ1Solving 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.
AtıfScopus79WoS59OpenAlex71İncele - MakaleAçık Erişim2011Scopus SJRQ2Geochemical and Sr-Nd isotopic characteristics of post-collisional calc-alkaline volcanics in the eastern pontides (NE Turkey); [Doǧu Pontidlerde (KD Türkiye) Çarpişma Sonrası Kalk-Alkalen Volkanizmanın Jeokimyası ve Sr-Nd İzotopik Karakterleri]
Kaygusuz, Abdullah; Arslan, Mehmet; Siebel, Wolfgang; Şen, Cüneyt
Major, trace element, K -Ar age and Sr-Nd isotopic data are presented for the Eocene Torul volcanics in the eastern Pontide orogenic belt (NE Turkey). The studied rocks are composed of basaltic andesitic, andesitic, trachyandesitic, and minor trachydacitic lavas associated with their pyroclastics. These rocks contain plagioclase (An2-44), hornblende (Mg#= 0.78-0.98), clinopyroxene (Wo43-46 En41-43 Fs10-15), biotite, quartz, and minor sanidine phenocrysts. K-Ar ages on hornblendes ages range from 43.99 (±2.59) to 33.45 (±2.32) Ma, within the Middle to Late Eocene. The volcanic rocks show calc-alkaline affinities and have medium to high K contents. They are enriched in large ion lithophile (LILE) and light rare earth elements (LREE), with pronounced depletion of high field strength elements (HFSE). The chondrite-normalized REE patterns (Lacn/Lucn= 4.0-9.8) show low to medium enrichment, indicating similar sources for the rock suite. Initial 87Sr/86Sr values vary between 0.70457 and 0.70511 and initial 143Nd/144Nd values between 0.51264 and 0.51278. The main solidification processes involved in the evolution of the volcanics consist of fractional crystallization with minor amounts of crustal contamination ± magma mixing. All evidence supports the conclusion that the parental magma(s) of the rocks probably derived from an enriched upper mantle, previously modified by subduction- induced metasomatism in a post-collisional geodynamic setting.
AtıfScopus75WoS75OpenAlex72İncele - MakaleYalnız künye2011Scopus SJRQ1Theoretical analysis the use of dimethyl ether and diethyl ether in a diesel engine
Sezer, Ismet
In this study, the use of dimethyl ether (DME) and diethyl ether (DEE) in diesel engines as alternative fuels investigated. A commercial suction (naturally-aspirated) direct injection (SDI) automobile diesel engine was chosen for investigation. Thermodynamic and performance analysis has been performed via a thermodynamic diesel engine cycle model. Thermodynamic and performance parameters computed and compared for diesel, DME and DEE fuels at two different situations. Results showed that DME and DEE presented the lower cylinder temperature and pressure, so a lower engine performance than diesel fuel for equal injection conditions. Brake power decreases about 32.1% and 19.4% at 4200 rpm while brake specific fuel consumption increases about 47.1% and 24.7% at 2200 rpm for DME and DEE, respectively. However, engine performance of DME and DEE extensively improves for the equal equivalence ratio condition, although more amount of fuel injection about 64 percent for DME and 32 percent for DEE is essential. The increments obtained by DME and DEE are about 13.6% and 6% in brake power at 4200 rpm compared to diesel. Brake specific fuel consumption is still higher about 43.5% for DME and 23.6% for DEE than diesel. Brake thermal efficiency of DME and DEE is generally better than diesel fuel.
AtıfScopus24WoS25İncele