Yazar "Ozturk, Beyhan" seçeneğine göre listele

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    ANDESITE WEATHERING CAUSED BY CRUSTOSE LICHENS, Xanthoria calcicola AND Diploschistes scruposus: A CASE STUDY
    (Parlar Scientific Publications (P S P), 2009) Erginal, A. Evren; Ozturk, Beyhan
    This paper discusses micro-morphological changes induced by lichen weathering at the interfaces between different types of lichen and their substrates composed of Miocene andesite, observed 10 km east of the city of Canakkale, NW Turkey. The evidences of physical and chemical weathering that occur at SW facing surfaces of lichen-encrusted andesite were studied based on energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), as well as inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses. Our results showed that both lichens contribute to the weathering of andesite, but with different rates. The weathered substrates under the lichens involved were determined to have increased amounts of Al, K, Ca, and Fe, but a decreased content of Si, suggesting either protective role of lichens against chemical weathering or precipitation of organic salts and iron oxides during lichen growth.
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    First note on marine-like cementation of Late Holocene beachrock, Iznik Lake (Turkey)
    (Versita, 2012) Erginal, Ahmet E.; Kiyak, Nafiye G.; Ozturk, Muhammed Z.; Yiğitbaş, Erdinç; Bozcu, Mustafa; Avcioglu, Mustafa; Ozturk, Beyhan
    Micro-fabric characteristics and optically stimulated luminescence (OSL) dating results are presented to discuss the controlling agents and timing of beachrock cementation on the fresh-water Iznik Lake shoreline. The beachrocks are made up of grain-supported polygenic conglomerate containing 20.42% carbonate with encrusted grains, basically as micrite coatings, isopachous aragonite rims, cryptocrystalline void fills and meniscus bridges. The optical ages of twelve samples yielded ages that range from 4.226 +/- 0.569 ka on the lowermost beds to 0.706 +/- 0.081 on the uppermost. This is the first report of precipitation of marine-like cements in Iznik Lake. The abundant aragonite-dominated cement is likely indicative of precipitation-prone dry evaporative conditions from the climatic optimum to the last millennia.
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    Investigation of Beachrock Using Microanalyses and OSL Dating: A Case Study from Bozcaada Island, Turkey
    (Coastal Education & Research Foundation, 2010) Erginal, Ahmet Evren; Kiyak, Nafiye Guenec; Ozturk, Beyhan
    We investigated the origin and absolute age of beachrock samples on Bozcaada Island, located on the northern Aegean Sea coast of Turkey, using energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM) analyses and optically stimulated luminescence (OSL) dating. Various types of cements were identified, such as micritic, meniscus, and biologic cements, revealing that the beachrock could have occurred as a result of the combined effects of marine-phreatic and supratidal cementation conditions. Optical dating results showed that the formation of beachrock ranged in age from 5.41 +/- 0.58 ka BP to 0.33 +/- 0.05 ka BP. However, much of the beachrock body (about 3 m in thickness) is drowned or submerged today, suggesting that submerged beachrocks extending to -5 m date to earlier times than the start of the cementation period discussed herein.
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    Investigation of the nature of slip surface using geochemical analyses and 2-D electrical resistivity tomography: a case study from Lapseki area, NW Turkey
    (Springer, 2009) Erginal, Ahmet Evren; Ozturk, Beyhan; Ekinci, Yunus Levent; Demirci, Alper
    The nature and subsurface structure of the slip surface of a landslide was studied on the basis of geochemical analyses and 2-D electrical resistivity tomography (ERT) survey. Head scarp and lateral slip surfaces of the landslide marked by clear slickensided shear planes were composed of the average amounts of clayey silt (32.5%) and sand (67.5%). Energy dispersive X-ray spectroscopy (EDX) data revealed the enrichment of Si (23.24%), Fe (12.2%), Al (9.51%) and C (8.34%) in the elemental composition of the disturbed slip surface. From X-ray diffractometry (XRD) data, six main clay types were determined, such as Volkonskoite, Halloysite, Ferrosilite, Saponite, Illite and Nontronite. The ERT survey displayed that the landslide developed as a reactivation on the upper part of an old landslide body.
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    Role and importance of Doppler ultrasound in the diagnosis of pulmonary sequestration: Report of two adolescent cases
    (Soc Romana Ultrasonografe Medicina Biologie-Srumb, 2013) Buyukkaya, Ramazan; Buyukkaya, Ayla; Ilce, Zekariya; Erdogmus, Besir; Kucuk, Adem; Ozturk, Beyhan
    Pulmonary sequestration is a rare pulmonary parenchymal anomaly. The localization of the aberrant artery and its relation with sequestration are of importance in the process of diagnosis in the preoperative period. The feeding artery can be identified by color Doppler ultrasonography. We report two cases of pulmonary sequestration in two adolescents, aged 11 and 13 years old, and this report documents the use of in which color Doppler ultrasound demonstrated the abnormal feeding artery. Color Doppler ultrasonography, a noninvasive and radiation-free imaging modality should be considered in the diagnostic algorithm of pulmonary sequestration.
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    Thermal indices in Western part of Turkey
    (Springer Heidelberg, 2015) Deniz, Zahide Acar; Ozturk, Beyhan
    In this study are used heat index, effective temperature, wet bulb globe temperature, and apparent temperature indices. Air vapor pressure, temperature, relative humidity, and wind speed data are very effective meteorological parameters over the sensitive temperature. Daily mean temperature (A degrees C), relative humidity (%), wind speed (m/s), and vapor pressure (hPa) data are used in this study. Using the thermal indices is calculated to long-term data from 49 stations distributed over the western part of Turkey. The Mann-Kendall test is applied to identify statistically significant trends at each series of thermal indices. The results of this study have shown that there are marked spatiotemporal variations in the thermal indices in the western part of Turkey. Increasing trends are stronger in summer compare with other season. Analysis are displayed that the increasing trends have shown warm-hot and discomfort days, especially during the summer season. High values of these indices are mainly connected to Azor high-pressure system and Monsoonal circulation and weakly etesian winds in summer.