277 research outputs found

    Effect of chill formation on the mechanical properties and microstructure of grey and nodular cast irons used in automotive industry

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    Cam shafts used in automobiles are produced by cast iron (grey cast iron, nodular cast iron) or steel. In this study, effect of chill formation on the surface of grey and nodular cast irons is investigated on the wear behavior, hardness, impact toughness and microstructure of grey and nodular cast irons. For this purpose, four types cam shaft made of grey cast iron with and without chill on the surfaces and nodular cast iron with and without chill on the surfaces, were casted. Mechanical tests were conducted after the camshafts have been produced by casting method. Surface hardness and wear resistance of grey and nodular cast irons have been improved by chill formation on the surfaces and it is concluded that the amount of wear on the surfaces of grey cast iron with chill and nodular cast iron with chill is almost the same. Maximum hardness value was obtained on the surface of grey cast iron with chill. The impact toughness has been found to decrease by chill formation. Maximum impact toughness value was obtained on nodular cast iron. Microstructures of grey cast iron with and without chill and nodular cast iron with and without chill were examined under optical microscope and worn surfaces of cast irons were examined by scanning electron microscopy (SEM). Wear mechanisms of the four types of cast iron were evaluated by SEM examination.Keywords: Cam shafts, Cast irons, Chill formation, Mechanical properties, Microstructure</span

    Duodenal Duplication Cyst with Recurrent Acute Pancreatitis: Report of a Case

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    Introduction:Duplication cyst can be occurred in any level of GI tract but the duodenal cysts are extremely rare. Most of the duplication cysts are detected in children. Duodenum duplication cysts are difficult to diagnose, as the presenting symptoms are nonspecific and are closely related to the type, size and location of the lesion. Both CT imaging and MRI can adequately identify a duodenal duplication cyst.Presentation of the case: We report an adult with recurrent episodes of acute pancreatitis who was diagnosed with ERCP. With the diagnosis of duodenal duplication cyst, we planned to perform surgical resection of the cyst.Conclusions: The surgical intervention for duodenal duplication cyst includes complete or partial surgical resection of the cyst. The location of the cysts in relation to the duodenum, especially to the ampulla, is important to determine the treatment strategy. Alternatively, duodenum duplication can be safely and effectively treated by different endoscopic interventions

    Effect of white mulberry extract on performance, anti-inflammatory and serum antioxidant parameters in diabetes-induced rats with streptozotocin

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    Bu çalışmada streptozotosin uygulanarak diyabet oluşturulan ratlarda beyaz dut ekstraktının kan serumlarında antioksidan etkileri, karaciğer dokusu histopatoloji, antienflamatuar özelliği ve ratlarda performans parametreleri üzerine etkisi araştırıldı. Deney grupları, kontrol grubu (K, n:5), streptozotosin uygulanan deney grubu 1 (DG 1, n:6), dut ekstraktı uygulanan deney grubu 2 (DG 2, n:7), streptozotosin ve dut ekstraktının birlikte uygulandığı deney grubu 3 (DG 3, n:6) olmak üzere toplam 24 adet hayvandan oluşturuldu. Karaciğer dokusunun yapısındaki vasküler konjesyon K ve DG 2’de 2 hayvanda, DG 3’te 1 hayvanda tespit edilmesine rağmen, DG 1’de bütün hayvanlarda belirlenmiştir (P<0,05). Karaciğer dokusunun yangı bulguları K’da görülmezken, DG 2’de 2 adet hayvanda hafif şekilde, DG 1’deki tüm hayvanlarda gözlenmiştir. Karaciğer dokusundaki dejenerasyon kontrol grubunda görülmezken, DG 2’de 1 adet, DG 1’de ise tüm hayvanlarda görülmüştür (P<0,01). Grupların serum dokularındaki seruloplazmin düzeyleri arasında önemli bir fark bulunmazken (P>0,05), Paraoksonaz (PON) aktiviteleri arasındaki fark önemli düzeyde olduğu tespit edilmiştir (P<0,05). Canlı ağırlık artışı kontrol grubunda 150,03 g., DG 2 de 114,93g. olarak gerçekleşmiştir (P<0,01). DG 1’de deneme süresince 1.33 g. canlı ağırlık artışı olurken DG 3’te ağırlık kaybı olmuştur (P>0,05). Sonuç olarak araştırmada ratlara uygulanan dut ekstraktının karaciğer dokusunda vasküler konjesyon, yangı ve dejenerasyon olgularını önemli derecelerde azalttığı ve antienflamatuar etkisi gösterebileceği söylenebilir.This study was conducted to investigate the effect of the white mulberry extract on histopathology, anti-inflammatory properties of liver tissue, blood serum antioxidant parameters and performance parameters of diabetes-induced rats with streptozotocin. Experimental groups consist of 24 animals which were divided into four groups; control group (C, n: 5), streptozotocin applied group 1 (DG 1, n: 6), mulberry extract applied group 2 (DG 2, n: 7), streptozotocin and mulberry extract experimental group 3 (DG 3, n:6), totally 24 animals were used. Although vascular congestion in the liver tissue was detected 2 animals in C and DG 2 groups and 1 animal in DG 3 group, vascular congestion was detected in all animals in DG 1 group. (P <0.05). Inflammatory findings of liver tissue were not seen in C, whereas it was mild in 2 animals in DG 2 and it was seen in all animals in the group of DG 1. Degeneration findings in liver tissue were not seen in C, but it was detected in 1 animal of DG 2 and all animals in DG 1 (P <0.01). There was no statistical difference between the ceruloplasmin levels of the groups (P> 0.05). Live weight gain in control group 150,03 g., DG 2 114.43 g. (P <0,01). 1.33 g. live weight gain and weight loss in DG 3 (P> 0.05). In conclusion, mulberry extract applied to rats significantly reduced vascular congestion, inflammation and degeneration findings in liver tissue and it can be said that mulberry extract has antiinflammatory effect

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