Ayşegül Yıldız

Distribution of Microflora, Meiofauna, and Macrofauna Assemblages in the Hypersaline Environment of Northeastern Aegean Sea Coasts

ABSTRACT Bassler-Veit, B.; Barut, I.F.; Meric, E.; Avsar, N.; Nazik, A.; Kapan-Yeşilyurt, S., and Yildiz, A., 2013. Distribution of microflora, meiofauna, and macrofauna assemblages in the hypersaline environment of northeastern Aegean Sea coasts. In this study, the morphology and taxonomy of microflora (charophytes and diatoms), meiofauna (benthic foraminifera and ostracoda), and macrofauna (mollusk) assemblages of the recent surface sediments from saltpans, hypersaline lagoons, and salt lakes of the Gulf of Saros (NW Turkey) were investigated. In total, 44 samples were collected from recent surface sediments in salt pans, hypersaline lagoons, and salt lakes of the Gulf of Saros (Enez Salt Lake, Isik Lake, Kuvalak Lake, Enez Gala Lake, Dalyan Lake, and Tasaltı Lake; Karagol, Vakif, and Erikli salt pans; and Uzungol Lagoon), Gallipoli Peninsula (salt pan), Biga Peninsula (Diremin and Azmak Lagoons and Dalyan Salt Lake), and Gokceada Island (salt lake). Surface sediments were collected, and some physical properties were measured, such as temperature, pH, and salt content. Grain size was determined and classified for each sample. In this study, foraminifera, ostracoda, and mollusca faunas in the normal marine environment were used as indicators and compared with the lagoonal environment, which has increased salt content during the summer months.

Diatomite as a novel composite ingredient for chitosan film with enhanced physicochemical properties

Practical applications of biopolymers in different industries are gaining considerable increase day by day. But still, these biopolymers lack important properties in order to meet the industrial demands. In the same regard, in the current study, chitosan composite films are produced by incorporating diatomite soil at two different concentrations. In order to obtain a homogeneous film, glutaraldehyde was supplemented to chitosan solution as a cross-linker. Compositing diatomaceous earth to chitosan film resulted in improvement of various important physicochemical properties compared to control such as; enhanced film wettability, increase elongation at break and improved thermal stability (264-277°C). The microstructure of the film was observed to haveconsisted of homogeneously distributed blister-shaped structures arised due to the incorporation of diatomite. The incorporation of diatomite did not influence the overall antioxidant activity of the composite films, which can be ascribe to the difficulty radicals formation. Chitosan film incorporated with increasing fraction of diatomite revealed a notable enhancement in the antimicrobial activity. Additionally with the present study, for the first time possible interactions between chitosan/diatomite were determined via quantum chemical calculations. Current study will be helpful in giving a new biotechnological perspective to diatom in terms of its successful application in hydrophobic composite film production.

Chronology of subduction and collision along the İzmir-Ankara suture in Western Anatolia: records from the Central Sakarya Basin

ABSTRACT Western Anatolia is a complex assemblage of terranes, including the Sakarya Terrane and the Tauride-Anatolide Platform that collided during the late Cretaceous and Palaeogene (80–25 Ma) after the closure of the Izmir-Ankara Ocean. Determining the precise timing at which this ocean closed is particularly important to test kinematic reconstructions and geodynamic models of the Mediterranean region, and the chronology of suturing and its mechanisms remain controversial. Here, we document the Cretaceous-Eocene sedimentary history of the Central Sakarya Basin, along the northern margin of the Neotethys Ocean, via various approaches including biostratigraphy, geochronology, and sedimentology. Two high-resolution sections from the Central Sakarya Basin show that pelagic carbonate sedimentation shifted to rapid siliciclastic deposition in the early Campanian (~ 79.6 Ma), interpreted to be a result of the build-up of the accretionary prism at the southern margin of the Sakarya Terrane. Rapid onset of deltaic progradation and an increase in accumulation rates in the late Danian (~ 61 Ma), as well as a local angular unconformity are attributed to the onset of collision between the Sakarya Terrane and the Tauride-Anatolide Platform. Thus, our results indicate that though deformation of the subduction margin in Western Anatolia started as early as the Campanian, the closure of the İzmir-Ankara Ocean was only achieved by the early Palaeocene.

KARACAÖREN YÖRESİ (NEVŞEHİR) DİATOMİTLERİNİN FİZİKOKİMYASAL ÖZELLİKLERİ VE KULLANIM ALANLARI

Bu calismada, Nevsehir ili, Urgup ilcesi, Karacaoren Yoresi’nde yuzeylenen ve Orta Anadolu Volkanizmasina bagli olarak olusan diyatomitlerin fizikokimyasal ozellikleri ve kullanim alanlari arastirilmistir. Inceleme alaninda, birisi Kuvaterner yasli gol cokelleri icerisinde (K1), digeri gec Miyosen- Pliyosen yasli Urgup formasyonu’nun Bayramhacili uyesi icerisinde yer alan gol cokellerinden (K2) olmak uzere 2 adet stratigrafik kesit olculmustur. Inceleme alaninda yer alan diyatomitlerin fizikokimyasal ozelliklerini ve kullanim alanlarini belirlemek amaciyla araziden alinan orneklere Maden Tetkik ve Arama Genel Mudurlugu (MTA) Laboratuvari’nda ates kaybi (1050 °C de), XRD, asitte ve suda cozunmeyen madde miktari, isi iletkenligi (101; 150 °C de ve ± 10 °C de), XRF, pH, toplam gozeneklilik, yogunluk, ozgul yuzey alani, gozenek hacmi, gozenek boyutu, beyazlik, dane boyu ve SEM analizleri yaptirilmis, analiz sonuclarinin degerlendirilmesi sonucunda, calisilan diyatomitlerin ticari degerlerinin oldugu, suzuculerde, dolgu ve yapi maddesi olarak ve silikat imalatinda dogrudan, hafif asindirici ve temizleyici olarak ve yalitim maddesi yapiminda ise isleme tabii tutularak kullanilabilecekleri ortaya konulmustur.