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1.
Multivariate analysis of heavy metal contents of sediments from Gumusler creek, Nigde, Turkey 总被引：2，自引：0，他引：2
In this study, heavy metal contents of samples from Gumusler creek in Turkey were studied and the metal contamination characteristics
were investigated. In this respect, considering the pollutant sites in the area, systematic sediment samples were collected
in a zone starting from the manifestation part of the water to the entrance of the Karasu creek in Gumusler town. Samples
were taken from lower section of the river bed at 30 stations along Gumusler creek, 13 km in length and their heavy metal
contents were analyzed with XRF Spectrometer. Correlation coefficients, element coefitic coefficient correlation, dendogram
hierarchical cluster, model summary and Annova analysis statistical methods were applied to data. Strong positive correlations
were determined for some elements which are believed to have possibly the same origin. In addition, mineralizations in the
area are thought to cause variation in metal contents. Results of chemical analysis show that soil limit values and clark
values were exceeded. The heavy metal accumulation in the creek is believed to be derived from non-operated Sb-Hg-W and Fe
quarries. 相似文献
2.
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
3.
Bulent Aktas Serife Yalcin Mehmet Albaskara Ali Arslan Gokhan Ceyhan 《Arabian Journal of Geosciences》2018,11(23):757
In this study, we investigated the structural properties of Urfa stone (US) doped with erbium oxide (Er2O3). Solid US was powdered by using an agate mortar, and its elemental composition was determined using inductive coupling plasma (ICP) methods. Varying amounts of Er2O3 (5, 10, 20, 30, and 40%) were added as a dopant to the US powder using mechanical alloying methods. The resultant samples were sintered at 1000 °C for 1 h. The structural properties of the Er2O3-doped US samples were subsequently investigated using X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FTIR), and photoluminescence methods. Results from the XRD analysis of the Er2O3-doped US powder indicated two crystalline phases: (1) calcium oxide (CaO) or lime and (2) Er2O3. After the samples were sintered at 1000 °C, CaO, Er2O3, calcium carbonate (CaCO3), and mixed crystalline phases were observed. Results from the FTIR analysis of the Er2O3-doped US samples indicated absorption bands at 711.91, 872.08, and 1396.87 cm?1 in the spectra. Finally, photoluminescence analysis results indicated a shift in the emission and excitation bands to longer and shorter wavelengths, respectively, in the solid state (non-aqueous media) US-Er complex. 相似文献
4.
The East Anatolian Fault Zone is a continental transform fault accommodating westward motion of the Anatolian fault. This study aims to investigate the source properties of two moderately large and damaging earthquakes which occurred along the transform fault in the last two decades using the teleseismic broadband P and SH body waveforms. The first earthquake, the 27 June 1998 Adana earthquake, occurred beneath the Adana basin, located close to the eastern extreme of Turkey’s Mediterranean coast. The faulting associated with the 1998 Adana earthquake is unilateral to the NE and confined to depths below 15 km with a length of 30 km along the strike (53°) and a dipping of 81° SE. The fixed-rake models fit the data less well than the variable-rake model. The main slip area centered at depth of about 27 km and to the NE of the hypocenter, covering a circular area of 10 km in diameter with a peak slip of about 60 cm. The slip model yields a seismic moment of 3.5?×?1018 N-m (Mw???6.4). The second earthquake, the 1 May 2003 Bingöl earthquake, occurred along a dextral conjugate fault of the East Anatolian Fault Zone. The preferred slip model with a seismic moment of 4.1?×?1018 N-m (Mw???6.4) suggests that the rupture was unilateral toward SE and was controlled by a failure of large asperity roughly circular in shape and centered at a depth of 5 km with peak displacement of about 55 cm. Our results suggest that the 1998 Adana earthquake did not occur on the mapped Göksun Yakap?nar Fault Zone but rather on a SE dipping unmapped fault that may be a split fault of it and buried under the thick (about 6 km) deposits of the Adana basin. For the 2003 Bingöl earthquake, the final slip model requires a rupture plane having 15° different strike than the most possible mapped fault. 相似文献
5.
6.
The Minim-Martap plateau bauxite deposit, located between the Minim and the Martap villages, is one of the 11 plateaus within the Minim-Martap bauxite region. The plateau has an elevation of 1294 m above sea level, with three to more 30 m thickness of bauxite horizon. These plateaus were formed as result of supergene weathering of volcanic rocks occurring as dissected flow basalt landscapes that form relatively flat plateau rising steeply from the surrounding granites. The bauxite deposit of the plateau is lateritic, with the surface of the plateau been completely covered by indurated caps. Seventeen bauxite samples were collected from the plateau and prepared for geochemical analysis. Whole rock analysis was carried out using the X-ray Fluorescence technique and ICP-MS was used for trace elements investigation. Statistical analysis reveals that average values of Al2O3 (54.87%), Fe2O3 (7.17%), SiO2 (2.44%), and TiO2 (4.54%) indicate the plateau bauxite deposit is an of a world class standard with very little impurities compared to the standard major element contents of bauxite (>?40% A12O3, less than <?20% Fe2O3, and less than <?8% combined SiO2). Abundant trace elements include Zr, Ce, Sr, V, Ba, La, Nd, Ga, and Nb. Weathering due to chemical alteration indices using the Ruxton ratio and CIA approaches revealed the plateau have undergone intense weathering process that formed the bauxite deposit. Three different classification systems indicate it as a low iron-rich bauxite deposit. Precursor rock investigation indicates the origin of the bauxite is mafic, basaltic andesite igneous rocks with intermediate pH (basic–acidic characteristic). 相似文献
7.
The influence of vertical ground motions on the seismic response of highway bridges is not very well understood. Recent studies suggest that vertical ground motions can substantially increase force and moment demands on bridge columns and girders and cannot be overlooked in seismic design of bridge structures. For an evaluation of vertical ground motion effects on the response of single‐bent two‐span highway bridges, a systematic study combining the critical engineering demand parameters (EDPs) and ground motion intensity measures (IMs) is required. Results of a parametric study examining a range of highway bridge configurations subjected to selected sets of horizontal and vertical ground motions are used to determine the structural parameters that are significantly amplified by the vertical excitations. The amplification in these parameters is modeled using simple equations that are functions of horizontal and vertical spectral accelerations at the corresponding horizontal and vertical fundamental periods of the bridge. This paper describes the derivation of seismic demand models developed for typical highway overcrossings by incorporating critical EDPs and combined effects of horizontal and vertical ground motion IMs depending on the type of the parameter and the period of the structure. These models may be used individually as risk‐based design tools to determine the probability of exceeding the critical levels of EDP for pre‐determined levels of ground shaking or may be included explicitly in probabilistic seismic risk assessments. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
8.
Emrah Yalcin 《水文科学杂志》2013,58(13):1588-1604
ABSTRACTThis study is an assessment of the return flow ratio of an irrigation abstraction using the flow records of a downstream stream-gauging station, with the example of the Kozluk scheme irrigated by diverted water from Garzan Creek flowing through the southeastern region of Turkey. In the planning reports of the major dam projects of the region, an unverified return ratio was assumed in eliminating the influence of this irrigation on the flow measurements of Garzan Creek. The correctness of this assumed return ratio is evaluated by analysing the monthly streamflow measurements of the Besiri station through a Soil and Water Assessment Tool (SWAT) model constructed with the coarse-scale topography, land use and soil data from open source databases. The results show the necessity of irrigation project-based return flow analyses using regional fine-scale datasets, instead of rule-of-thumb assumptions, to determine the effects of irrigation activities on flow regimes more accurately. 相似文献
9.
The range of response frequencies for which spectral ordinates obtained from accelerograms may be considered reliable is limited by several factors, primary among them being the effects of filters that are routinely applied to remove noise from the records. Considerable attention has been focused on the low‐frequency limit of the usable spectral ordinates because of various engineering applications requiring long‐period spectral accelerations or displacements but only recently have rational approaches to selecting the high‐frequency limit been proposed. Since there are applications for which the high‐frequency spectral ordinates are important, the approaches to this issue presented in the recent studies are reviewed and their application to the ground‐motion database from Europe and the Middle East is explored. On the basis of the results of these analyses, it is concluded that a large proportion of this dataset can be used to provide reliable estimates of response spectral ordinates at much shorter periods than may have previously been considered feasible. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
10.
A. Ugur Ozcan Gunay Erpul Mustafa Basaran H. Emrah Erdogan 《Environmental Geology》2008,53(8):1731-1741
The universal soil loss equation (USLE) is an erosion model to estimate average soil loss that would generally result from
splash, sheet, and rill erosion from agricultural plots. Recently, use of USLE has been extended as a useful tool predicting
soil losses and planning control practices by the effective integration of the GIS-based procedures to estimate the factor
values on a grid cell basis. This study was performed for five different lands uses of Indağı Mountain Pass, Cankırı to predict
the soil erosion risk by the USLE/GIS methodology for planning conservation measures in the site. Of the USLE factors, rainfall-runoff
erosivity factor (USLE-R) and topographic factor (USLE-LS) were greatly involved in GIS. These were surfaced by correcting
USLE-R site-specifically using DEM and climatic data and by evaluating USLE-LS by the flow accumulation tool using DEM and
watershed delineation tool to consider the topographical and hydrological effects on the soil loss. The study assessed the
soil erodibility factor (USLE-K) by randomly sampled field properties by geostatistical analysis. Crop management factor for
different land-use/land cover type and land use (USLE-C) was assigned to the numerical values from crop and flora type, canopy
and density of five different land uses, which are plantation, recreational land, cropland, forest and grassland, by means
of reclassifying digital land use map available for the site. Support practice factor (USLE-P) was taken as a unit assuming
no erosion control practices. USLE/GIS technology together with the geostatistics combined these major erosion factors to
predict average soil loss per unit area per unit time. Resulting soil loss map revealed that spatial average soil loss in
terms of the land uses were 1.99, 1.29, 1.21, 1.20, 0.89 t ha−1 year−1 for the cropland, grassland, recreation, plantation and forest, respectively. Since the rate of soil formation was expected
to be so slow in Central Anatolia of Turkey and any soil loss of more than 1 ton ha−1 year−1 over 50–100 years was considered as irreversible for this region, soil erosion in the Indağı Mountain Pass, to the great
extent, attained the irreversible state, and these findings should be very useful to take mitigation measures in the site. 相似文献