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1.
A. Savaş Arapoğlu Ezgi Yalçınkaya A. Emrah Yükselci 《Astrophysics and Space Science》2018,363(10):215
A five-dimensional cosmological model including a single perfect fluid is studied in the framework of dynamical system analysis. All the critical points of the system are listed with their stability properties and some representative phase diagrams are explicitly shown. It is found that the stabilization of extra dimension is possible and the observed flatness of the three-dimensional space is provided for certain ranges of the equation of state parameter of the fluid. The model suggested here can be considered as a simplified model for examining the possible effects of the extra dimensions in the early universe. 相似文献
2.
K–Ar dating of mineral separates extracted from various granitoid rock units of the eastern Pontides and central Anatolia,
Turkey, has provided some new insights unravelling various stages of the Neo-Tethyan convergence system, which evolved with
northward subduction between the Eurasian plate (EP) to the north and the Tauride-Anatolide platform (TAP) to the south along
the İzmir-Ankara-Erzincan suture (IAES) zone. Arc-related granitoid rocks are only encountered in the eastern Pontides and
yield K–Ar cooling ages of both Early Cretaceous (138.5 ± 2.2 Ma) (early arc), and Late Cretaceous, ranging from 75.7 ± 0.0
to 66.5 ± 1.5 Ma (mature arc), respectively. The multi-sourced granitoids of the eastern Pontides, with a predominant mantle
component and K–Ar ages between 40 and 50 Ma, are considered to be a part of post-collisional slab break-off magmatism accompanied
by tectonic denudation of pre-Late Cretaceous granitoid rocks following juxtaposition of the EP and the TAP around 55–50 Ma
in the eastern Pontides. The K–Ar cooling ages of collision-related S-, I- and A-type granitoids in central Anatolia reflect
good synchronism between 80 and 65 Ma, suggesting a coeval genesis in a unique geodynamic setting but with derivation from
various sources—namely, purely crustal, purely mantle and/or of mixed origin. This sort of simultaneous generation model for
these S-I-A-type intrusives seems to be consistent with a post-collisional lithospheric detachment related geodynamic setting.
I-type granodioritic to tonalitic intrusives with K–Ar cooling ages ranging from 40 to 48 Ma in east-central Anatolia are
interpreted to have been derived from a post-collisional, within-plate, extension-related geodynamic setting following the
amalgamation of the EP and the TAP in east-central Anatolia. 相似文献
3.
Doğan Bülent Aşci Metin Karakaş Ahmet Pekşen Ertan Erener Arzu Çepni Murat Selim Yavuzyilmaz Selin Alahmad Mohammad Sertçelik Fadime Sertçelik İbrahim Kurtuluş Cengiz 《Natural Hazards》2021,109(2):1675-1716
Natural Hazards - The Northern Branch of the North Anatolian Fault System controls and deforms the Izmit Basin and the Sapanca Lake Basin in the study area. Unlike the Sapanca Lake Basin, the... 相似文献
4.
Hüseyin Çaldırak Bedri Kurtuluş 《Journal of the Indian Society of Remote Sensing》2018,46(9):1353-1364
This study explores the evidence of recharge locations using hydrogeochemical and physicochemical measurements in an alkaline lake, Lake Salda, in Burdur, Turkey. In-situ measurements have been performed using a conductivity–temperature–depth device to map the physicochemical dynamic of the lake. Water and sediment samples were collected on the surface and floor of the lake. A seismic study was also carried out in order to observe the geometry of the lake floor. In addition, thermal distribution was mapped using the thermal band of Landsat 7 ETM+ and Landsat 8 satellite images. Temperature and specific conductance measurements were mapped using a new technique, Empirical Bayesian Kriging (EBK), from the lake’s surface to the floor. According to interpolation maps obtained from the EBK, possible water inputs were observed close to a fault at the south-eastern part of the lake. The results of thermal band imaging also reveal the probability of a fault effecting the recharge on the surface. The results of water and sediment samples present a richness in Mg2+ and Fe2+ elements respectively on the floor of the lake. Finally, seismic results show some possible recharge zones on the floor of the lake, and sediment results indicate that there should be peridotite occurrence below the alluvium unit. 相似文献
5.
Halil İbrahim Gülşen-Rothmund Özgür Avşar Ulaş Avşar Bedri Kurtuluş Evren Tunca 《Environmental Earth Sciences》2018,77(14):546
Elemental accumulation, distribution and relationship profiles for sediment samples taken at 81 localities in the Köyce?iz Lake were investigated. Spatial distribution maps for ten elements (Cu, Pb, Zn, Ni, Cr, Co, Mn, Mo, Al, Fe) were created using the ordinary kriging interpolation method. Statistical tests revealed that the sediments taken from areas close to the Namnam (NamSM) and Karg?cak (KarSM) stream mouths have the highest element content. In addition, sediments close to NamSM have the highest contamination, according to contamination degree and modified contamination degree values. On the other hand, sediments close to KarSM have the highest value on the pollution load index. The enrichment factor and contamination factor values of Cr and Co, and especially Ni, close to NamSM are striking and have significantly higher values compared to the rest of the lake. There are strong correlations between these three elements, which were also confirmed by cluster analysis. Ni is the element having the highest value on the geoaccumulation index. In addition, according to the toxic unit results, it was found that 84–89% of the element-based toxic effect in the lake is due to Ni alone. According to the mean effect range median quotient values, the sediments of Köyce?iz Lake have a potential to show toxic effects of at least 76% in living organisms, which is due to the high levels of Ni. According to the mean probable effect low quotient value, it has been determined that Köyce?iz Lake is at a “highly impacted” level, which is the worst possible value on the quality scale. 相似文献
6.
Numerical investigation of stochastic response of an elevated water tank to random underground blast loading 总被引：2，自引：2，他引：0
Kemal Hacıefendioğlu Kurtuluş Soyluk Fahri Birinci 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(4):599-607
This paper presents a stochastic finite element seismic response study of a water tank subjected to random underground blast-induced
ground motion. Such tanks contain water and hazardous chemical substances, which implies significant risk to human life, serious
environmental pollution, and considerable economic loss. The random blast-induced ground motion is represented by power spectral
density function and applied to each support point of the three dimensional finite element model of the elevated water tank–fluid
interaction system. A parametric study is conducted to estimate the effects of the blast-induced ground motion on the stochastic
response of the elevated water tank system. Therefore, the analyses are carried out for different values of the charge weight
and the distance from the charge centre. Additionally, in order to investigate the effect of the fluid on the stochastic response
of the elevated water tank, three cases with different water levels are considered in the analyses. Finally, it is observed
that underground blast loading considerably changes the stochastic behavior of the elevated water tank system. 相似文献
7.
A methodology for seismic microzonation and earthquake damage scenarios may be considered as composed of two stages. In the first stage, microzonation maps with respect to estimated earthquake characteristics on the ground surface are generated for an investigated urban area. The effects of local geological and geotechnical site conditions are taken into account based on site characterization with respect to representative soil profiles extending down to the engineering bedrock. 1D site response analyses are performed to calculate earthquake characteristics on the ground surface using as many as possible, hazard compatible real acceleration time histories. In the second stage, vulnerability of buildings and pipeline systems are estimated based on site-specific ground motion parameters. A pilot study is carried out to evaluate seismic damage in a district in Istanbul, Turkey. The results demonstrate the significance of site characterization and site response analysis in calculating the earthquake characteristics on the ground surface in comparison to simplified empirical procedures. 相似文献
8.
In this paper, stochastic analysis of a cable-stayed bridge subjected to spatially varying ground motions is performed. While the ground motion is described by power spectral density (PSD) function, the spatial variability of ground motions is taken into account with the incoherence and the wave-passage effects. The incoherence effect is examined by taking into account two extensively used models. As the effect of the wave-passage effect is investigated by using various wave velocities, the effect of local soil conditions where the bridge supports are constructed is outlined by using homogeneous firm, medium and soft soil conditions. Solutions obtained for the spatially varying ground motions are compared with those of the specialised cases of the ground motion model. Stationary as well as the transient response analyses are performed for the considered bridge model. It is concluded that spatial variability and propagation effects of ground motions have important effects on the dynamic behaviour of the bridge and the variability of the ground motions should be included in the stochastic analysis of cable-stayed bridges. 相似文献
9.
Abrasivity Assessment of Granitic Building Stones in Relation to Diamond Tool Wear Rate Using Mineralogy-Based Rock Hardness Indexes 总被引：1，自引：1，他引：0
Nurdan Güneş Yılmaz 《Rock Mechanics and Rock Engineering》2011,44(6):725-733
The objective of the present study was to determine the abrasive wear potential of granites in circular sawing using some
mineralogy-based rock hardness indexes. A literature study indicated that little or no attention has been given to assessing
this kind of relationship in the field of stone processing. To accomplish this objective, sawing experiments were performed
on nine different granites used widely as building and decorative stone materials. The measured sawblade-specific wear rates
were correlated with three different rock hardness indexes attained by combining the percentage content of hard mineral constituents
with their known hardness values. Statistical analysis of the experimental data revealed that rock hardness indexes that are
based on both Vickers hardness number and Rosiwal hardness could be accepted as reliable indicators of granite abrasivity.
These two indexes were also found to correlate well with the average power drawn during the process. However, the rock abrasivity
index based on Mohs relative scratch hardness did not show statistically significant correlations with sawblade wear rate
and power drawn. Although quartz percentage content is regarded as an important abrasivity parameter by practitioners, the
observations made here indicate that consideration of quartz percentage content alone is not sufficient to describe the abrasive
potential of granites, and thus incorporation of other hard mineral constituents could be more suitable. 相似文献
10.
C. Kurtuluş B. Doğan F. Sertçelik M. Canbay H. M. Küçük 《Marine Geophysical Researches》2009,30(2):121-134
The Edremit Gulf, which developed during the Neogene-Quaternary, is a seismically active graben in NW Anatolia (Turkey) surrounded
by the Sakarya continent. The sedimentary deposits in the gulf overlie the bedrock unconformably and can be separated into
two parts as upper and lower deposits based on similarity of their seismic characteristics, and because the contact between
them is clear. The lower deposits are characterized in the seismic profiles by the absence of well defined, continuous reflectors
and are strongly disturbed by faults. A tectonic map and structural model of the Edremit Gulf was derived from interpreting
21 deep seismic profiles trending NE–SW and NW–SE within the gulf. Two fault systems were distinguished on the basis of this
compilation. The NNW–SSE trending parallel faults are low-angle normal faults formed after compression. They controlled and
deformed the lower basin deposits. A syncline and anticline with a broad fold-curvature length resulted in folds that developed
parallel to basin boundaries in the lower basin deposits. The ENE–WSW trending high-angle faults have controlled and deformed
the northern basin of the Edremit Gulf. The folds developed within the northern lower deposits originated from the listric
geometry of the faults. These faults are normal faults associated with regional N–S extension in western Anatolia. The Edremit
Gulf began to open under the control of low-angle NNW–SSE trending faults that developed after the compression of western
Anatolia in an E–W direction in the early Neogene. Subsequently, regional N–S extensional stress and high-angle normal faults
cut the previous structures, opened the northern basin, and controlled and deformed the lower basin deposits in the gulf.
As a result, the Edremit Gulf has not been controlled by any strike-slip faults or the Northern Anatolian Fault. The basin
developed in the two different tectonic regimes of western Anatolia as an Aegean type cross-graben from the Neogene to Holocene. 相似文献