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61.
The coastal water quality of Çanakkale Dardanelles (Turkey) was assessed based on bacteriological data and physical–chemical parameters. Total coliform (TC), fecal coliform (FC), and enterococci (ENT) bacteria along with physicochemical parameters were measured monthly up to a year at 12 different sampling sites located through both coastal lines of the strait. The fecal bacteria were abounded at several sampling sites such as B1, B3, G3, and G4 due to direct wastewater discharges and septic leakages or overloading. Storm water runoff and sediment resuspension were important pathways for the transport of coliform and ENT bacteria to the Dardanelles, as the region receives high precipitation and strong winds for most part of the year. The values of pH, temperature, and salinity were in typical ranges for the studied area. The microbiological and physicochemical data were correlated individually and in combination. The best fit correlations for bacterial data were attained between TC and FC or TC and ENT (R = 0.67 or ?0.68), while those for the combined data were obtained for TC with temperature (R = 0.94) and TC with salinity (R = ? 0.70). 相似文献
62.
This paper presents the variations of vibration under different traffic conditions on the Fatih Sultan Mehmet suspension bridge in Istanbul, Turkey.The main intention is to determine the vibration amplifications under heavy-traffic as opposed to no-traffic conditions. This is the first study in this particular area that has been performed on this bridge, over which an average of 200,000 cars pass daily. Two full-scale ambient vibration surveys were carried out on two different days to determine the response of the bridge to diverse traffic conditions. Initial measurements were taken as the bridge experienced heavy stress conditions caused by rush-hour traffic. Secondary measurements were recorded after closing the bridge to traffic. The data were analyzed to gauge the vibration effects of heavy-traffic conditions on the bridge and to determine the effects of different traffic conditions on the free vibration characteristics of the bridge. The analyses were performed utilizing different amplification methods. Results show that there are important differences in the amplifications of the vibration amplitudes. Especially heavy-traffic on the bridge causes the vibration response of the bridge to be intensified in comparison to no-traffic conditions. Additionally, predominant frequencies are shifted as a direct result of traffic load acting on the bridge. Even more importantly and is probably analogous for all long-span bridges, is the fact that any movement causing vibration on the bridge is carried and amplified along its length. These significant amplifications indicate the important effect of varying traffic loads and how the bridge responds to the diverse movements it experiences. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
63.
The occurrence frequencies of dayside ion conics with various conic angles are obtained as a function of altitude from Exos-D (Akebono) observations. We made a model calculation of ion conic evolution to match the observation results. The observed occurrence frequencies of ion conics with 80° to 90° conic angle are used as an input to the model and the occurrence frequencies of ion conics with smaller conic angles are numerically calculated at higher altitudes. The calculated occurrence frequencies are compared with the observed ones of ion conics with smaller conic angles. We take into account conic angle variation with altitude in both adiabatic and non-adiabatic cases, horizontal extension of ion conics due to E × B drift, and evolution to elevated conics and ion beams in the model. In the adiabatic case, the conic angle decreases with increasing altitude much faster than was observed. The occurrence frequency of small-angle conics is much larger than the observed value without E × B drift and evolution to the other UFIs. An agreement is obtained by assuming non-adiabatic variation of conic angles with altitude and an ion E × B drift to gyro velocity ratio of 0.08 to 0.6, depending on geomagnetic activities. 相似文献
64.
Mustafa Yanalak Elif Sertel Nebiye Musaoglu Cengizhan Ipbuker Sinasi Kaya 《Journal of the Indian Society of Remote Sensing》2011,39(2):135-146
Spatial mapping from space using high-resolution satellite sensor data instead of conventional data collection techniques
widely gained popularity. This study aims to analyze the planimetric and thematic accuracy of high-resolution OrbView-3 and
IKONOS orthoimages. OrbView-3 and IKONOS images of a test area were acquired and these images were geometrically corrected
using rational polynomial functions to conduct accuracy assessment. 40 Ground Control Points (GCPs) generated from static
Global Positioning System (GPS) survey were used in the orthorectification procedure. 182 Test Points (TPs) produced from
terrestrial surveying technique were used to analyze the accuracy of orthorectifications. Root Mean Square Error (RMSE) values
obtained for GCPs and TPs were used to determine the planimetric accuracy of these images. Thematic accuracy analyses were
conducted in radiometric and spatial base. Transects, lines and polygons were created to analyze the radiometric quality of
data sets and to determine minimum distinguishable distance and distinguishable area. Both planimetric and thematic accuracy
analyses illustrated that OrbView-3 and IKONOS images could be used to create 1:10000 scale map of the concerned region with
appropriate planimetric and thematic quality. 相似文献
65.
Assessment of seawater intrusion to the agricultural sustainability at the coastal area of Carey Island, Selangor, Malaysia 总被引:3,自引:0,他引:3
Mohamad Faizal Tajul Baharuddin Samsudin Taib Roslan Hashim Mohd Hazreek Zainal Abidin Nur Islami Rahman 《Arabian Journal of Geosciences》2013,6(10):3909-3928
Groundwater suitability for agriculture in an island with limited recharge area may easily be influenced by seawater intrusion. The aim of this study was to investigate seawater intrusion to the suitability of the groundwater for oil palm cultivation at the ex-promontory land of Carey Island in Malaysia. This is the first study that used the integrated method of geo-electrical resistivity and hydro-geochemical methods to investigate seawater intrusion to the suitability of groundwater for oil palm cultivation at two different land cover condition. The relationship between earth resistivity, total dissolved solids and earth conductivity was derived with crop suitability classification according to salinity, used to identify water types and also oil palm tolerance to salinity. Results from the contour conductivity maps show that area facing severe coastal erosion and area still intact with mangrove forest exhibits unsuitable groundwater condition for oil palm at the unconfined aquifer thickness of 15 and 31 m, respectively. Based on local sea-level rise prediction and Ghyben–Herzberg assumption (sharp interface), the condition in the study area, especially in severe erosion area, by the twenty-first century will no longer be suitable for oil palm plantation. The application of geo-electrical method combined with geochemical data, aided with the information on environmental history and oil palm physiography, has demonstrated that the integration of techniques is an effective tool in defining the status of agricultural suitability affected by salinity at the coastal aquifer area. 相似文献
66.
Gökhan Karcioğlu Sabri Bülent Tank Aysan Gürer Elif Tolak Çiftçi Tülay Kaya Mustafa Kemal Tunçer 《Studia Geophysica et Geodaetica》2013,57(2):292-308
A magnetotelluric survey was performed at the Çatalca Region, west of Istanbul, Turkey with the aim of investigating geoelectrical properties of the upper crust near the Çatalca Fault and its vicinity. Broadband magnetotelluric data were collected at nine sites along a single southwest-northeast profile to image the electrical resistivity structure from surface to the 5 km depth. The dimensionality of the data was examined through tensor decompositions and highly two-dimensional behavior of the data is shown. Following the tensor decompositions, two-dimensional inversions were carried out where E-polarization, B-polarization and tipper data were utilized to construct electrical resistivity models. The results of the inversions suggest: a) the Çatalca Fault extends from surface to 5 km depth as a conductive zone dipping to southwest; b) the thickness of the sedimentary cover is increasing from SW to NE to 700 m with low resistivity values between 1–100 Ωm; c) the crystalline basement below the sedimentary unit is very resistive and varies between 2000–100000 Ωm; d) a SW-dipping resistivity boundary in the northeastern part of our profile may represent the West Black Sea Fault. 相似文献
67.
Z. Z. Abidin J. P. Leahy A. Wilkinson P. Reich W. Reich R. Wielebinski 《New Astronomy Reviews》2003,47(11-12):1151
We present preliminary results from mapping the high-latitude galactic polarization with the Effelsberg Telescope at λ21 cm. Structures on the resulting maps are mostly on the scale of several degrees. The results show detection of polarization over most of the field, at the level of tens of percent of the synchrotron emission. The evidence of more structure in Stokes Q and U rather than in
suggests the existence of Faraday rotation. 相似文献
68.
69.
The rapidly developing mining sector in recent years has also brought environmental problems together. At the beginning of these problems are mine process wastes produced in high quantities from mines every year. The waste material at 90% and the concentrate chromite at 10% are obtained in the chromite ore enrichment plants. This significant amount of waste creates pollution in nature visually and physically. The aim of the study is to determine the advantages of using foamed concrete as a building material, to reduce the production cost of foamed concrete, to produce alternative solutions for rehabilitation, and to eliminate environmental pollution. The chromite enrichment wastes obtained from Fethiye, Köyce?iz, Denizli and Burdur regions were used as aggregates in the production of foamed concrete. In this study, compressive strength experiments were carried out according to TS EN 1354, thermal conductivity experiments were carried out according to TS EN 12664. As a result, it has been observed that chromite waste (dunite) can be used in the production of foamed concrete under certain conditions. 相似文献
70.
Seismic-Magnetic Effect of Swarms and Strong Earthquakes along Gulf of Aqaba Fault Segments in Egypt
Geotectonics - Seismo-magnetic investigation can play an important role in the investigation of various phenomena connected with earthquakes. The main target of this study is to investigate the... 相似文献