The accumulation of silver and gold in Lemna gibba L. exposed to secondary effluents     

Ahmet Sasmaz  Erdal Obek 《Chemie der Erde / Geochemistry》2012,72(2):149-152

Aquatic plants are used as a practical and effective method to remove toxic metals from secondary-treated municipal wastewater. In this study, Lemna gibba was investigated for its capacity to remove silver (Ag) and gold (Au) from secondary effluents. L. gibba was collected from a natural lake and then acclimatized to the effluent in situ. The concentration of toxic elements in the plant material was monitored as a function of time over 7 days. L. gibba accumulated significant amounts of Ag and Au for six days from initiation of the experimental study. The highest accumulations were 2303% for Ag and 247% for Au. However, after six days, the rate of Ag and Au accumulation in L. gibba declined, as saturation levels had been reached in the plant tissues. The metal accumulating property of L. gibba can also be commercially exploited to recover Au and Ag from wastewater and mining wastes.  相似文献   

Monitoring Spatial and Temporal Land Use/Cover Changes; a Case Study in Western Black Sea Region of Turkey     

M. Alkan  M. Oruc  Y. Yildirim  D. Z. Seker  K. Jacobsen 《Journal of the Indian Society of Remote Sensing》2013,41(3):587-596

Rapid land use/land cover changes have taken place in many cities of Turkey. Land use and land cover changes are essential for wide range of applications. In this study, Landsat TM satellite imageries date from 1987, 1993, 2000 and 2010 were used to analyse temporal and spatial changes in the Western Black Sea Region of Turkey. Zonguldak and Eregli two largest and economic important cities which have been active coal mining and iron fabric areas. Maximum Likelihood Classification technique was implemented and the results were represented in classes of open area, forest, agricultural, water, mining, urban and pollution in the sea. Urban areas on both cities increased from 1987 to 2010. The agricultural and open areas from 1987 to 2010 decreased in parallel to land use and land cover change in both cities. Meanwhile, forest areas increased continuously with about 20 % from 1987 to 2010 in both cities. As industrial activity, the coal fields doubled from 1987 to 2010.  相似文献   

Third Body Problem in the Eclipsing Binary Star TV Cassiopeia     

Ahmet Erdem 《Celestial Mechanics and Dynamical Astronomy》2002,82(2):133-141

The aim of this work is to search for some evidences for the presence of unseen companion(s) in the eclipsing binary star TV Cassiopeia using its O—C diagram. Assuming that the light-time effect is responsible for the periodic components on the O—C diagram, the set of orbital parameters were derived using Irwin's (1959) method. The resulting orbital parameters and mass of the hypothetical third body are physically acceptable. Lacking other proofs of the third body presence, however, the hypothesis can be treated as a probable case only.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

Biodegradation effects over different types of coastal rocks     

Murat Gül  Ahmet Özbek  Fahri Karayakar  Mehmet Ali Kurt 《Environmental Geology》2008,55(7):1601-1611

Modern coastal areas have natural and transported rocks (armourstone) on which various types of organisms live. Burrowing, boring and feeding by these organisms can destroy or modify the coastal rocks and hence change the coastal morphology. Two rock types and three dominant types of organisms have been studied in Mersin Bay, Eastern Mediterranean of southern Turkey. In this study area, Plio-Quaternary conglomerates and variously aged limestone armourplates have been affected by Phoronida worms, bivalve Brachidontes pharaonis (Fischer P. 1870) and the limpet Patella sp. Phoronida colonies were found covering the hard substratum as a mat and form tubular endolithes of 35.0 mm depth and 1.5 mm diameter, whilst Brachidontes pharaonis (Fischer P. 1870) form 44 mm deep vase-shaped gastrochaenolites. The bioerosive activity of Limpet Patella sp., found intertidal and within the spray zone, cannot be significantly observed on the rocks over short time periods. The soft sandy matrix of the conglomerates present were found to disintegrate by bioerosional processes, with the released gravels being transported and deposited onto the beach. Within the armourstone limestone blocks, a maximum of 44.0 mm deep holes developed after 50–60 years. However, these biological activities do not threaten the stability of the blocks due to their hard and homogeneous internal structure. Furthermore, the organism colonies that cover these rocks as a strong mat (maximum 29.0 mm) act to protect their surfaces from further biological attack and wave action.  相似文献   

The mineralogy,geochemistry, and suitability for ceramic applications of Akharım (Afyonkarahisar,W Turkey) kaolinitic clay     

M. Kuşcu  Ahmet Yıldız 《Arabian Journal of Geosciences》2016,9(7):510

Kaolinitic clays associated with sedimentary rocks cover widespread in the Yeniköy formation from the Akhar?m district, (Afyonkarahisar, W Anatolia). Due to the proximity to the ceramic industry areas such as Kütahya and U?ak Province of Turkey, the clays in the Akhar?m district have been intensively exploited for the last few years. The Akhar?m kaolinitic clays were hosted by Middle-Upper Miocene-aged Yeniköy formation and divided into two parts as northeastern and southwestern via normal fault. The alteration degree increases from lower levels to surface in the NE part of deposit. Besides layered structure in their N70° W/30° SW direction and gray-beige, yellowish brown colored in SW part. This study focused on mineralogy, geochemistry, and ceramic properties of kaolinitic clays. X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, chemical, physical, and mechanical tests were conducted on studied samples from the wall of clay quarry. Akhar?m clay deposits consist of mainly kaolinite and quartz. Additionally, they include smectite, biotite, feldspar, jarosite, calcite, and hematite minerals. Akhar?m clays are characterized with their moderate plasticity (PL = 17.07–24.09), low water absorption (3.64–9.53 wt.%), low linear shrinkage (8.08–15.55 wt.%), high bending strength (17.72–32.69 N/mm²), and ideal lightness values (L* = 46.50–82.74) and color values (a* = 4.71–29.87; b* = 14.67–28.72). These properties vary related with mineralogical and geochemical features of Akhar?m clays. In conclusion, Akhar?m clays have desired specifications for floor and wall t to their mineralogical, geochemical, and ceramic properties.  相似文献   

An Extended Approach of Particle Swarm Optimization for Shoreline Extraction from RASAT Imagery     

Hatice Catal Reis  Bülent Bayram  Salih Bozkurt  Abdulkadir Ince  Nusret Demir  Dursun Zafer Seker 《Journal of the Indian Society of Remote Sensing》2018,46(8):1223-1232

This study presents an extended shoreline detection approach from pansharpened images of Turkish RASAT satellite which covers red, green and blue bands of the optical spectrum with 15 m ground resolution and panchromatic band with 7.5 m spatial resolution. The Lake Ercek of Turkey has been selected as the study area, which is a tectonic lake and home to a variety of water birds. The satellite images of the lake taken in 2013 and 2014 were considered for analysis. The proposed shoreline extraction system consists of a sequence of image processing steps in which simple linear clustering (SLIC) and particle swarm optimization (PSO) are the main components. SLIC was used to create superpixels that form basis for object-based image analysis while PSO was employed for classifying objects into corresponding classes. The resulting images still contained unwanted artefacts; therefore, a post-processing step was performed to improve the accuracy of segmentation by applying thresholding, morphological processing, and manual editing for noise removal. The proposed framework was applied on two temporal RASAT images to test the variations of defined parameter settings. The success of the proposed system was to obtain shorelines with satisfying accuracy without using NIR band. Finally, the extracted shorelines were vectorised and compared with manually digitized shorelines from pansharpened satellite images for accuracy assessment.  相似文献   

Generation of 1D and 2D flood maps of Sakarya river passing through Geyve district of Sakarya city in Turkey     

Ceribasi  Gokmen  Ceyhunlu  Ahmet Iyad 《Natural Hazards》2021,105(1):631-642

Natural Hazards - In recent years, changes in precipitation caused by climate change resulting from global warming lead to great floods in world. This climate change causes drought in some regions,...  相似文献   

Adaptation of hurricane risk perception scale to earthquake risk perception and determining the factors affecting women's earthquake risk perception     

Mızrak  Sefa  Özdemir  Ahmet  Aslan  Ramazan 《Natural Hazards》2021,109(3):2241-2259

Natural Hazards - Worldwide studies show that gender is an important variable affecting disaster risk perception and that women have high levels of disaster risk perception. The objective of this...  相似文献   

Evaluation of blast effects on reinforced concrete buildings considering Operational Modal Analysis results     

Alemdar Bayraktar  Temel Türker  Ahmet Can Altunişik  Barış Sevim 《Soil Dynamics and Earthquake Engineering》2010,30(5):310-319

Seismic protection of buildings under risk can be achieved by increasing the knowledge about the behaviour of existing structures. Operational Modal Analysis is a powerful tool used for this purpose all over the world. It provides the dynamic characteristics of structures under operational conditions or some particular environmental issues such as blasts and earthquakes. The main objective of this study is to evaluate blast effects on a reinforced concrete (RC) building considering experimentally determined dynamic characteristics. The study consists of three phases: the measurement of vibration characteristics of blasting, the theoretical modal analysis of the inspected building, and experimental verification of dynamic characteristics using modal testing. The vibration characteristics of blasting are measured around the inspected building on hard soil using a geophone set. The initial analytical model of the building is constructed according to the in-situ investigation on building. The theoretical modal analysis results are verified by carrying out modal testing on the RC building. The Operational Modal Analysis method is used for the extraction of the dynamic characteristics of the building, and blast vibrations are taken into account as environmental vibrations. The effects of blasting on the reinforced concrete building are introduced by assessing the vibration of blasting with the dynamic characteristics of the building.  相似文献   

Petrographical and geochemical investigation of the Triassic marbles associated with Menderes massif metamorphics,Kavaklıdere,Muğla,SW Turkey     

Metin Bağcı  Yaşar Kibici  Ahmet Yıldız  Ömer Tezcan Akıncı 《Journal of Geochemical Exploration》2010

Vast marble deposits occur in a cover sequence of the Menderes Massif, SW Turkey. Four major marble deposits are recognized in Mu?la province based on the stratigraphic levels. These are Permo-Carboniferous aged black marbles (1), Triassic aged marbles (2), Upper Cretaceous aged marbles (3), and Paleocene aged pelagic marbles (4). This study deals with Triassic aged marbles of the southern part of the Menderes Massif. The Triassic marbles from SW Turkey consist of two big marble horizons in the Çayboyu (ÇM) and Kestanecik (KM) regions. The characteristic samples are collected from different stratigraphic levels in marble deposits in the ÇM and KM horizons. Mineralogical and major, trace, and rare earth element (REE) analyses of marble, limestone, and schist were conducted on these samples to reveal their petrographical and geochemical characteristics. The ÇM horizon is represented by calcitic marble layers. Nickel, cobalt, manganese, and iron elements filled in fractures, fissures, and intergranular spaces of calcite crystals and these elements give the pinky colour to the marble from the ÇM horizon. KM marbles were deformed, metamorphosed, and recrystallized under greenschist facies P–T conditions. As a result of the metasomatic reaction of magnesium and manganese rich fluids with marbles, dolomite, and manganese, minerals such as rhodochrosite and pyrolusite have crystallized along vein walls and layers in the KM horizon. Dolomitization was determined in KM marbles, whereas ÇM marbles show the character of limestone. MgO, MnO, Fe₂O₃, Ni, and Zn contents of marbles from the KM horizon are higher than those of ÇM marbles due to metasomatic reactions. The Sr content in white coloured marbles ranges between 11.20 ppm and 112.20 ppm and this concentration reaches up to 272.70 ppm due to metasomatic reactions and fluid intake. The REE content of Triassic marbles is independent of the abundance of carbonate and the REE enrichment observed due to syn-metamorphic fluid flow. The significant negative Eu anomaly in REE patterns indicates that the protoliths of Triassic marbles are carbonate rocks of sedimentary origin.  相似文献