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251.
This study reports the levels of organochlorine pesticides (OCPs, α‐, β‐, γ‐ and Δ‐HCHs, p,p′‐DDE, p,p′‐DDD and p,p′‐DDT), polychlorinated biphenyls (PCBs, PCB 28, 52, 101, 153, 138 and 180 congeners) and polybrominated diphenyl ethers (PBDEs, PBDE 47, 99, 100, 153 and 154 congeners) in 45 individual human milk samples collected from Konya City, Turkey. Average concentrations of ΣHCHs, ΣDDTs, ΣPCBs and ΣPBDEs were 22.62, 37.10, 104.95 and 67.34 ng/g lipid wt., respectively. No significant differences in investigated pollutants were found between primiparous and multiparous mothers. There was no correlation between levels of each group of pollutants in human milk and the age of mothers. Moreover, there was no significant difference in the levels of ΣDDTs, between mothers who have eaten fish more than once a week and those who consumed fish less than once. An analysis of the infant exposure to DDTs, HCHs and PCBs via mother's milk indicated that the estimated daily intakes of these pollutants were below the guideline proposed by the World Health Organization (WHO) and the Health Canada which means that there is definitely no concern on children health. 相似文献
252.
This study aimed to investigate the site characterization of the Senirkent Basin(Isparta) by using the microtremor(H/V) and surface wave analysis(ReMi) methods. Senirkent district, which is located on the foothill of the Kap? Mountain, are prone to seismic and landslide hazards. After the last landslip disaster(1995), the city has continued to develop on the alluvial basin. The microtremor data collected at 41 stations were analyzed. The predominant frequency and the amplification of the soil were found to be in the range of 1.8–6.6 Hz and 0.8–6.8, respectively. These are 4.0-6.8 Hz and 1-2.5 around the slope of the Kap? Mountain and 0.8-3.6 Hz and 3.0-6.6 at alluvium deposits of the valley. The ReMi data collected along 41 profiles were analyzed to obtain a V_(s30) map. The soil classifications were done by using V_(s30) values according to NEHRP soil classification criteria. The results showed that the southern area of the study had better soil conditions with V_(s30) between 360-1160 m/s and soil class between C and B. The alluvium deposits on the north are relatively low with V_(s30) in the range of 260-360 m/s and soil class D. 相似文献
253.
The Cerchar abrasivity index (CAI) is one of the most widely known index method for identification of rock abrasivity. It is a simple and fast testing method providing reliable information on rock abrasiveness. In this study, the relationships between the CAI and some rock properties such as uniaxial compressive strength (UCS), point load strength, Brazilian tensile strength and Schmidt rebound hardness, and equivalent quartz content (EQC) are examined. The relationships between the CAI and drill bit lifetime is also investigated and the type of drill bit wear observed is mentioned. Additionally, the CAI is modeled using simple and multiple linear regression analysis based on the rock properties. Drill bit lifetime is also modeled based on the CAI. The results show that the CAI increases with the increase of the UCS, point load strength, Brazilian tensile strength, L-type and N-type Schmidt rebound hardness, and the EQC. It is concluded that the higher and the lower bit lifetime are obtained for marl and andesitic-basaltic formation, respectively. Moreover, flushing holes, inserted button, button removal, and failures of button on the bits are determined as the type of drill bit wear. The modeling results show that the models based on the UCS and the EQC give the better forecasting performances for the CAI. 相似文献
254.
Zafer Aslan Dilber Erdem İrfan Temizel Mehmet Arslan 《International Geology Review》2017,59(14):1764-1785
Palaeogene and Neogene volcanic rocks are widespread on the Biga Peninsula of Northwest Turkey. These rocks were formed during the Eocene, Oligocene–Miocene, and late Miocene, and the early Miocene ?apç? volcanic rocks in the Bal?kesir area consist of andesitic lava flows and associated pyroclastics. Temperatures, pressures, and oxygen fugacities calculated for the hornblendes in these andesitic rocks are 903–930°C, 3.3–4.8 kbar, and –9.91 to –11.88, respectively, and for the biotites they are 755–788°C, 1.30–1.74 kbar, and –14.88 to –13.98, respectively. SHRIMP U–Pb dating of zircons from three andesite samples gave ages of 22.72 ± 0.19, 22.97 ± 0.23, and 18.72 ± 0.17 Ma (early Miocene), and these are regarded as crystallization ages. Geochemical analyses show that the volcanic rocks are mainly high-K and calc-alkaline, and have high contents of large-ion lithophile elements and low contents of high-field strength elements, revealing that they evolved from parental magmas that were derived from an enriched subcontinental lithospheric mantle source. The chondrite-normalized rare earth element patterns of the rocks are concave upwards with LaCN/LuCN = 11.9–21.2 and EuCN/Eu* = 0.84–0.92, implying significant fractional crystallization of hornblende during their evolution. According to the petrological data with regional geology, Neogene magmatic activity on the Biga Peninsula has a post-collisional feature, and was closely related to slab break-off geodynamic model after collision of Tauride–Anatolide Block and Sakarya continent. 相似文献
255.
Mohsen Henchiri Walid Ben Ahmed Andrea Brogi Mehmet Cihat Alçiçek Ramdhane Benassi 《Geodinamica Acta》2017,29(1):20-41
The Quaternary stratigraphic record of Jebel El Mida, composed of continental deposits, is a useful example of concomitant travertines and alluvial deposition in an extensional setting. Travertine deposition occurred in a faulted Pleistocene alluvial fan giving rise to seven (recognised) facies interfingering with five other alluvial ones. The travertine depositional events indicate a tectonically driven evolution from terraced slope (facies group FC1–FC6) to a travertine fissure ridge-type depositing phase (facies group of FC1–FC7). Interfingering between travertine and alluvial facies indicates the co-existence of adjacent and time-equivalent depositional environments. The travertine deposition resulted from deep origin hydrothermal fluids channelled along damaged rocks volumes associated to a regional fault system, named as the Gafsa Fault (GF). The travertine–terrigenous succession in Jebel El Mida highlights the major role played by the GF in controlling: (i) the hydrothermal fluid flow, still active as also indicated by the numerous thermal springs aligned along the fault zone; (ii) paleoflow directions, discharge locations, volume, rate and fluctuations of the water supply. The paleoclimatic correlation with adjacent localities reveals that, at that time, humid episodes could have contributed to the recharge of the hydrothermal system and to the deposition of alluvial sediments. 相似文献
256.
This paper describes the constitutive behavior and particle-scale kinematics of granular materials in three-dimensional (3D) axisymmetric triaxial testing using discrete element method (DEM). PFC3D code was used to run the DEM simulations using a flexible membrane boundary model consisting of spherical particles linked through flexible contact bonds. The overall deformation behavior of the specimen was then compared with the specimen with rigid boundary and experimental measurements. Computed tomography was used to track the evolution of particle translation and rotation within a laboratory triaxial specimen in 3D. The DEM model of the flexible membrane specimen successfully predicted the stress–strain behavior when compared with laboratory experiment results at different confining pressures. The DEM results showed that the rigid specimen applies a uniform deformation and leads to non-uniformities in the confining stress along the particle-boundary interface in the lateral direction. In contrast, the flexible specimen better replicates the uniformly applied confining stress of a laboratory triaxial experiment. The 3D DEM simulations of the specimen with flexible membrane overpredicted particle translation and rotation in all directions when compared to a laboratory triaxial specimen. The difference between the particle translation and rotation distributions of DEM specimens with rigid and flexible membrane is almost negligible. The DEM specimen with flexible membrane produces a better prediction of the macroscopic stress–strain behavior and deformation characteristics of granular materials in 3D DEM simulations when compared to a specimen with rigid membrane. Comparing macroscale response and particle-scale kinematics between triaxial simulation results of rigid versus flexible membrane demonstrated the significant influence of boundary effects on the constitutive behavior of granular materials. 相似文献
257.
In this study, total heavy metal content of soil and their spatial distribution in Sar?seki-Dörtyol district were analyzed and mapped. Variable distance grids (0.5, 1.0 and 2.0 km) were established, with a total of 102 soil samples collected from two different soil depths (0–5 and 5–20 cm) at intersections of the grids (51 sampling point). Soil samples were analyzed for heavy metals (Cd, Co, Cr, Cu, Pb, Zn, Mn, Fe, and Ni). The most proper variogram models for the contents of all heavy metal were spherical and exponential ones. The ranges of semivariograms were between 1.9 and 31.1 km. According to the calculated geoaccumulation (I geo) values, samples from both soil depths were classified as partly to highly polluted with Cd and Ni and partly polluted with Cr and as partly polluted-to-not polluted with Pb and not polluted with Cu, Fe and Mn. Similar results were also obtained when evaluated by the enrichment factor. The contamination levels of the heavy metals were Ni > Cd > Cr > Pb > Zn > Cu > Co > Fe > Mn in decreasing order. The soils in the study area are contaminated predominantly by Cd and Ni, which may give rise to various health hazards or diseases. Cadmium pollution results primarily from industrial activities and, to a lesser extent, from vehicular traffic, whereas Ni contents in the study area result from parent material, phosphorus fertilizer, industries, and vehicles. 相似文献
258.
Evaluation of groundwater quality and contamination around fluorite mineralization,Kaman region,Central Anatolia,Turkey 总被引:1,自引:0,他引:1
Groundwater can be exposed to pollution and therefore the quality will be affected in areas of fluorite mineralization. Distribution
of fluorite mineralization in the area, its formation type and hydrogeological characteristics of these rocks are a factor
of the pollution parameters in groundwater. Syenite, nephelinesyenite and micro gabbro type alkaline rocks are exposed in
the Kaman region. Hydrothermal fluorite mineralization is formed in fractures and fissures of the syenite and nepheline-syenites
in the study area. The fluoride values of these rocks vary between 480–11990 ppm. These high fluoride concentrations in the
rocks result in fluoride contamination in groundwater. 相似文献
259.
The Plio-Quaternary conglomeratic sets within the marine environment of the Viranşehir coast (W Mersin, S Turkey) are responsible
for the evolution of sandy and gravely beaches due to their control on various factors such as sea floor irregularity, wave
energy, and organic activity. The conglomeratic sets close to the shoreline (50–150 cm) act as wave breakers, creating hard
substratum and high energy, well-oxygenated environment for organisms like Patella sp., Phoronida worms and Brachidontes pharaonis (Fischer P. 1870). The boring activities of these organisms have disintegrated the sandy matrix of these sets. Finer-grained
matrix sediments have been transported to the interset and open sea, while cobble–pebbles have been carried landwards and
have created imbricated gravely beach deposits without matrix. Sandy beach is evolving where the conglomeratic sets away from
the shoreline (5.0–10.0 m). In this example, sets form a bar; causing fivefold division as backshore, berm, surf zone, bar
and offshore from land to sea. Poorly sorted, cobbles-pebbles cobbles and pebbles are found associated with the high-energy
environments of bars, whilst well-sorted sands are observed in low energetic environments on shore. The sets and recent shell
fragments are the main sources of coastal sediments in Viranşehir. However, the amount of shell fragments decrease towards
the active river mouth. This is due to sediment and fresh water influx from the river causing deteriorated temperature, salinity
and light penetration of the marine environment resulting in less organic diversity.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
260.