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Çimento üretimi yüksek sıcaklıklarda (1400-1500°C) gerçekleştirilebildiği için önemli ölçüde enerji tüketimini zorunlu kılmaktadır. 1 ton çimento üretimi için yaklaşık olarak 1 ton CO2 salınımı meydana gelmektedir. Dünyada toplam CO2 salınımının %7'sinin çimento üretiminden kaynaklandığı bilinmektedir. Ekonomik ve çevresel nedenlerden dolayı çimentoya alternatif bağlayıcı arayışları giderek önem kazanmaktadır. Geopolimerler, doğal ve atık puzolanların alkali aktivatörler (NaOH ve Na2SiO3) ile aktive edilmesi sonucu üretilen alümin silikat tipi bağlayıcı malzemelerdir. Bu çalışmanın amacı, Nevşehir yöresinden temin edilen volkanik tüfün geopolimer bağlayıcı üretiminde kullanılabilirliğini araştırmaktır. Bu amaçla, aktivatör tipi, aktivatör konsantrasyonu ve kür sıcaklığı parametrelerinin modifikasyonu ile optimum özelliklere sahip geopolimer hamur, harç ve beton numuneler üretilmiştir. Sonraki aşamada, deneysel olarak elde edilmiş optimum özelliklere sahip geopolimer betonun bazı mekanik, durabilite ve mikroyapı özelliklerine nano silis, mikro silis ve polimer katkılarının etkisi araştırılmıştır. Yapılan deneysel çalışmalar sonucunda volkanik tüfün geopolimer hamur, harç ve beton üretiminde kullanılabileceği belirlenmiştir. Kullanılan katkıların volkanik tüf esaslı geopolimer betonların bazı mekanik, durabilite ve mikroyapı özelliklerini önemli ölçüde etkilediği tespit edilmiştir. Because cement production can be carried out at high temperatures (1400-1500°C), it requires significant energy consumption. Approximately 1 ton of CO2 is emitted for 1 ton of cement production. It is known that 7% of total CO2 emissions in the world is due to cement production. The search for alternative binding to cement is becoming increasingly important due to economic and environmental reasons. Geopolymers are aluminosilicate type binding materials produced by the activation of natural and waste pozzolans with alkali activators (NaOH ve Na2SiO3). The aim of this study is to investigate the usability of volcanic tuff supplied from Nevşehir region in the production of geopolymer binders. For this purpose, geopolymer paste, mortar and concrete specimens with optimum properties were produced by modification of activator type, activator concentration and curing temperature parameters. In the next step, the effects of nano silica, micro silica and polymer additves on some mechanical, durability and microstructure properties of geopolymer concrete which has experimentally obtained with optimum properties were investigated. As a result of the experimental studies, it has been revealed that volcanic tuff can be used in the production of geopolymer paste, mortar and concrete. It has been found that the additives used have a significant effect on some mechanical, durability and microstructural properties of volcanic tuff based geopolymer concrete. 239

This paper presents the effect of elevated temperatures up to 700 degrees C on compressive strength and water absorption of two alkali-activated aluminosilicate composites (one of them is river sand aggregate geopolymer concrete; the other one is crushed sand aggregate geopolymer concrete) and ordinary Portland cement based concretes. To obtain binding geopolymer material, Elaz ferrochrome slag was ground as fine as cement, and then it was alkali activated with chemical (NaOH and Na2SiO3). Geopolymer concrete samples were produced by mixing this binding geopolymer material with aggregates. At each target temperature, concrete samples were exposed to fire for the duration of 1h. Fire resistance and water absorption of geopolymer and ordinary Portland cement concrete samples were determined experimentally. Experimental results indicated that compressive strength of geopolymer concrete samples increased at 100 degrees C and 300 degrees C temperatures when compared with unexposed samples. In geopolymer concrete samples, the highest compressive strength was obtained from river aggregates ones at 300 degrees C with 37.06MPa. Water absorption of geopolymer concrete samples increased at 700 degrees C temperature when compared with unexposed samples. However, a slight decrease in water absorption of concrete samples was observed up to 300 degrees C when compared with unexposed samples. SEM and X-ray diffraction tests were also carried out to investigate microstructure and mineralogical changes during thermal exposure. Copyright (c) 2016 John Wiley & Sons, Ltd.

Vascular involvement can be seen in up to 40% of patients with Behcet syndrome (BS), the lower-extremity vein thrombosis (LEVT) being the most common type. The aim of the current study was to compare venous Doppler findings and clinical features between BS patients with LEVT and control patients diagnosed as having LEVT due to other causes. All consecutive 78 patients (71 men, 7 women; mean age 38.6 ± 10.3 years) with LEVT due to BS and 50 control patients (29 men, 21 women; mean age 42.0 ± 12.5 years) who had LEVT due to other causes, or idiopathic, were studied with the help of a Doppler ultrasonography after a detailed clinical examination. Patterns of venous disease were identified by cluster analyses. Clinical features of chronic venous disease were assessed using 2 classification systems. Venous claudication was also assessed. Patients with BS were more likely to be men, had significantly earlier age of onset of thrombosis, and were treated mainly with immunosuppressives and less frequently with anticoagulants. Furthermore, they had significantly more bilateral involvement, less complete recanalization, and more frequent collateral formation. While control patients had a disorganized pattern of venous involvement, BS patients had a contiguous and symmetric pattern, involving all deep and superficial veins of the lower extremities, with less affinity for crural veins. Clinical assessment, as measured by the 2 classification systems, also indicated a more severe disease among the BS patients. In line, 51% of the BS patients suffered from severe post-thrombotic syndrome (PTS) and 32% from venous claudication, whereas these were present in 8% and 12%, respectively, among the controls. Among BS patients, a longer duration of thrombosis, bilateral femoral vein involvement, and using no anticoagulation along with immunosuppressive treatment when first diagnosed were found to be associated independently with severe PTS. Lower-extremity vein thrombosis associated with BS, when compared to LEVT due to other causes, had distinctive demographic and ultrasonographic characteristics, and had clinically a more severe disease course.

Objective Patient position on the operating table is generally prone or lateral decubitis (LD) in endoscopic disc surgery. The effects of these positions on the critical working zones such as Kambin Triangle (KT) and neural foramina are not clear in the current literature. The purpose of this anatomical study was to compare the area of the critical working zones in the lumbosacral region in different operation positions. Methods Bilateral KT areas (KTA) and neural foraminal areas (FA) of L4-L5 and L5-S1 levels in prone and LD positions were calculated in 32 healthy volunteers (16 male and 16 female) depending on the freehand ROI measurements on the MR images. KTA and FA values for each side and level in prone and LD positions were statistically compared with paired samples T test. Results Mean left KTA values in prone and right LD positions respectively, were 0.58 cm2 and 0.69 cm2 for L4-L5 and 0.69 cm2 and 0.78 cm2 for L5-S1 levels. Mean right KTA values in prone and left LD positions respectively, were 0.54 cm2 and 0.65 cm2 for L4-L5 and 0.69 cm2 and 0.81 cm2 for L5-S1 levels. The KTA differences between prone and LD positions for both levels and both sides were statistically significant (p=0.05). For the FA values, only the difference between prone and LD positions for L5-S1 level on the right side was statistically significant (p=0.05). Conclusion Our study quantitatively showed that the KTA is wider in LD position than in prone position in L4-L5 and L5-S1 levels. DOI: 10.3944/AOTT.2015.14.0233This abstract belongs to the un-edited version of the article and is only for informative purposes. Published version may differ from the current version.

Elazığ ili Maden ilçesinde bulunan ve dünya rezervinin %10?unu oluşturan kromit yatakları, Elazığ ferrokrom tesislerinde işlenmektedir. Bu fabrikada ana ürünün dışında oluşan birçok yan ürünün atılması, uzaklaştırılması, depolanması veya yok edilmesi büyük bir sorun oluşturmaktadır. Bu yan ürünlerden bir tanesi olan Elazığ Ferrokrom cürufu (EFC) şimdiye kadar inşaat sektöründe çimento katkı maddesi ve agrega olarak kullanılmış olup, üzerinde birçok araştırma yapılmıştır. Ancak EFC?nin alkali ile aktivasyonu ve aktivasyon sonucu oluşan geopolimer bağlayıcı madde ile üretilen betonların özellikleri henüz bilinmemektedir. Bu çalışmada, EFC çimento inceliğinde öğütülmüş ve aktivatör (Na2SiO3 ile NaOH birleşmesi ile oluşan) ile birleştirilerek bağlayıcı madde oluşturulmuştur. Bu bağlayıcı madde ve agrega (dere agregası ve kırma kum) kullanılarak geopolimer beton numuneler üretilmiştir. Üretilen geopolimer beton numunelerin basınç dayanımları (3, 7 ve 28 gün), bazı fiziksel özellikleri, yangın dayanımları (100, 200, 300, 400, 500, 600 ve 700oC) ve mikro yapıları incelenmiştir. Ayrıca elde edilen sonuçlar normal Portland çimentolu beton numunelerle karşılaştırılmıştır.Deney sonuçlarına göre, EFC ve aktivatör kullanılarak üretilen dere agregalı geopolimer beton numunelerde 28 günlük basınç dayanımı değerinin yaklaşık 35 MPa olduğu görülmüştür. Bu değer aynı kür şartları altında üretilen normal Portland çimentolu beton numunelerde elde edilen basınç dayanım değerinden (31.8 MPa) büyüktür. Yangın sonrası basınç dayanımlarında ise kontrol numunelerine göre, bütün karışımlarda 100 ve 300 ?C sıcaklıklarda basınç dayanımı değerlerinde artış olduğu görülmüştür. 700 0C?de ise bütün beton numunelerinde minimum basınç dayanımı elde edilmiştir.Anahtar Kelimeler:Geopolimer çimento, Elazığ ferrokrom cürufu, alkali-aktivatör, yangın dayanımı The chromite deposits which are 10% of the world reserves located within the boundaries of Maden town of Elazig are processed in Elazığ ferrochrome plants. The disposal, removal and storage of by-products which are produced apart from the main product is a big problem. Many studies have been done over Elazığ Ferrochrome slag (EFC) which is one of these by-prıducts and it was used in the construction industry as cement additive and aggregate. However, the activation of EFC with alkali and the properties of concretes produced with geopolimer binding substance as a result of activation with alkali and EFC is still unknown.In this study, EFC was ground as fine as cement and geopolymer binding material was made by combining ground granulated EFC with activator (formed by combination of NaOH with Na2SiO3). Geopolymer concrete samples were produced by using this binding material aggregates (river sand and crushed sand). Compressive strength, some physical properties, fire resistance (100, 200, 300, 400, 500, 600 and 700oC) and microstructures of geopolymer concrete samples were obtained experimentally. In addition, it was compared to concrete samples produced using by normal Portland cement.As a result of experiments, 28 days compressive strength of geopolymer concrete by using EFC and activator was obtained nearly 35 MPa. This value, the compressive strength (31.8 MPa) obtained from river aggregates geopolymer concrete, is greater than for the same conditions by using normal Portland cement. Compressive strength of all samples exposed temperature at 100 and 300 °C increased compared to control samples. At 700 °C, minimum compressive strength was obtained for all concrete samples.Keywords: Geopolymer cement, Elazığ ferrochrome slag, alkali-activator, fire resistance. 131

Intratesticular arteriovenous malformations (AVMs) are extremely rare benign incidental lesions of the testis. Ultrasonography (US) generally reveals a hypoechoic solid mass within the testicular parenchyma. We describe a patient with intratesticular AVM which was found incidentally during workup for infertility. The gray-scale and Doppler US appearance of an intratesticular AVM and the differential diagnosis have been presented. Based on the gray-scale, US appearance differentiation from malignant testicular tumors is difficult. Doppler US examination aids in the diagnosis by demonstrating the vascular nature of the tumor.