Stresses in FGM pressure tubes under non-uniform temperature distribution

Eraslan, Ahmet N. Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.4

The effects of material nonhomogeneity and nonisothermal conditions on the stress response of pressurized tubes are assessed by virtue of a computational model. The modulus of elasticity, the Poisson's ratio, the yield strength, and the coefficient of thermal expansion, are assumed to vary nonlinearly in the tube. A logarithmic temperature distribution within the tube is proposed. Under these conditions, it is shown that the stress states and the magnitudes of response variables are affected significantly by both the material nonhomogeneity and the existence of the radial temperature gradient.

THE TURKISH ATTEMPT TO REPORM IN IRAQ : 1880-1920

ERASLAN, Gezmi 한국이슬람학회 2004 한국이슬람학회논총 Vol.14 No.1

북아프리카 이슬람 원리주의 운동의 중요한 한 갈래로 여겨지는 사누시 종단의 오스만 제국의 술탄과의 관계, 나아가 1차세계대전에 이은 터기 독립전쟁기간에 터기의 독립영웅 무스타파 케말 파샤와의 특별한 관계를 다루었다. 전세계 이슬람 세력을 결집하여 서구열강으로부터 오스만 제국를 지키려던 술탄 압둘 하미드의 범이슬란운동에 힙입어 세이크 사누시는 오스만 제국의 특별한 의호를 받으며 정치적 활동과 조세 징수에서 많은 특혜를 누렸다. 오스만 왕정이 멸망만 이후에는 케말 파샤에 협력하여 터기 독립전쟁을 도왔다. 이교도인 침략자를 성스런 이슬람 제국의 땅에서 몰아내는 것은 신성만 투쟁이라고 보았기 때문이다. 사누시의 이슬람 영향력을 지속해서 감시하고 통제해 온 영국의 방해의 결국 그의 이슬람 통합 여파는 처지 않았지만. 오늘날 그의 종교적 권위는 이미 1920년대 탄탄한 길을 다지고 있었다.

The Turkish Attement to Reform in Iraq(1880-1920)

Cezmi Eraslan 한국이슬람학회 2004 한국이슬람학회논총 Vol.14 No.1

북아프리카 이슬람 원리주의 운동의 중요한 한 갈래로 여겨지는 사누시 종단의 오스만 제국의 술탄과의 관계, 나아가 1차세계대전에 이은 터키 독립전쟁 기간에 터키의 독립영웅 무스타파 케말 파샤와의 특별한 관계를 다루었다. 전세계 이슬람 세력을 결집하여 서구열강으로부터 오스만 제국를 지키려던 술탄 압둘 하미드의 범이슬람운동에 힘입어 세이크 사누시는 오스만 제국의 특별한 보호를 받으며 정치적 활동과 조세 징수에서 많은 특혜를 누렸다. 오스만 왕정이 멸망한 이후에는 케말 파샤에 협력하여 터키 독립전쟁을 도왔다. 이교도인 침략자를 성스런 이슬람 제국의 땅에서 몰아내는 것은 신성한 투쟁이라고 보았기 때문이다. 사누시의 이슬람 영향력을 지속해서 감시하고 통제해 온 영국의 방해로 결국 그의 이슬람 통합 여파는 크지 않았지만, 오늘날 그의 종교적 권위는 이미 1920년대 탄탄한 길을 다지고 있었다.

Stresses in FGM pressure tubes under non-uniform temperature distribution

Ahmet N. Eraslan 국제구조공학회 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.4

The effects of material nonhomogeneity and nonisothermal conditions on the stress response of pressurized tubes are assessed by virtue of a computational model. The modulus of elasticity, the Poisson’s ratio, the yield strength, and the coefficient of thermal expansion, are assumed to vary nonlinearly in the tube. A logarithmic temperature distribution within the tube is proposed. Under these conditions, it is shown that the stress states and the magnitudes of response variables are affected significantly by both the material nonhomogeneity and the existence of the radial temperature gradient.

The effect of silane applied to glass ceramics on surface structure and bonding strength at different temperatures

Tevfik Yavuz,Oguz Eraslan 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.2

PURPOSE To evaluate the effect of various surface treatments on the surface structure and shear bond strength (SBS) of different ceramics. MATERIALS AND METHODS 288 specimens (lithium-disilicate, leucite-reinforced, and glass infiltrated zirconia) were first divided into two groups according to the resin cement used, and were later divided into four groups according to the given surface treatments: G1 (hydrofluoric acid (HF)+silane), G2 (silane alone-no heat-treatment), G3 (silane alone-then dried with 60℃ heat-treatment), and G4 (silane alone-then dried with 100℃ heat-treatment). Two different adhesive luting systems were applied onto the ceramic discs in all groups. SBS (in MPa) was calculated from the failure load per bonded area (in N/mm2). Subsequently, one specimen from each group was prepared for SEM evaluation of the separated-resin–ceramic interface. RESULTS SBS values of G1 were significantly higher than those of the other groups in the lithium disilicate ceramic and leucite reinforced ceramic, and the SBS values of G4 and G1 were significantly higher than those of G2 and G3 in glass infiltrated zirconia. The three-way ANOVA revealed that the SBS values were significantly affected by the type of resin cement (P<.001). FIN ceramics had the highest rate of cohesive failure on the ceramic surfaces than other ceramic groups. AFM images showed that the surface treatment groups exhibited similar topographies, except the group treated with HF. CONCLUSION The heat treatment was not sufficient to achieve high SBS values as compared with HF acid etching. The surface topography of ceramics was affected by surface treatments.

Critical evaluation of fracture strength testing for endodontically treated teeth: a finite element analysis study

Emel Uzunoglu-Özyürek,Selen Küçükkaya Eren,Oğuz Eraslan,Sema Belli 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.2

Objectives: The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars. Methods: A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. 135° angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses. Results: The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root. Conclusions: The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.

Critical evaluation of fracture strength testing for endodontically treated teeth: a finite element analysis study

Uzunoglu-Ozyurek, Emel,Eren, Selen Kucukkaya,Eraslan, Oguz,Belli, Sema The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.2

Objectives: The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars. Methods: A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. $135^{\circ}$ angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses. Results: The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root. Conclusions: The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.

Gastric Carcinoma with Bone Marrow Metastasis: A Case Series

Ekinci, Ahmet Siyar,Bal, Oznur,Ozatli, Tahsin,Turker, Ibrahim,Esbah, Onur,Demirci, Ayse,Budakoglu, Burcin,Arslan, Ulku Yalcintas,Eraslan, Emrah,Oksuzoglu, Berna The Korean Gastric Cancer Association 2014 Journal of gastric cancer Vol.14 No.1

Gastric cancer is a major cause of cancer-related mortality. At the time of diagnosis, majority of the patients usually have unresectable or metastatic disease. The most common sites of metastases are the liver and the peritoneum, but in the advanced stages, there may be metastases to any region of the body. Bone marrow is an important metastatic site for solid tumors, and the prognosis in such cases is poor. In gastric cancer cases, bone marrow metastasis is usually observed in younger patients and in those with poorly differentiated tumors. Prognosis is worsened owing to the poor histomorphology as well as the occurrence of pancytopenia. The effect of standard chemotherapy is unknown, as survival is limited to a few weeks. This report aimed to evaluate 5 gastric cancer patients with bone marrow metastases to emphasize the importance of this condition.

Gastric Carcinoma with Bone Marrow Metastasis: A Case Series

Ahmet Şiyar Ekinci,Öznur Bal,Tahsin Özatlı,İbrahim Türker,Onur Eşbah,Ayşe Demirci,Burçin Budakoğlu,Ülkü Yalçıntaş Arslan,Emrah Eraslan,Berna Öksüzoğlu 대한위암학회 2014 Journal of gastric cancer Vol.14 No.1

Gastric cancer is a major cause of cancer-related mortality. At the time of diagnosis, majority of the patients usually have unresectable or metastatic disease. The most common sites of metastases are the liver and the peritoneum, but in the advanced stages, there may be metastases to any region of the body. Bone marrow is an important metastatic site for solid tumors, and the prognosis in such cases is poor. In gastric cancer cases, bone marrow metastasis is usually observed in younger patients and in those with poorly differentiated tumors. Prognosis is worsened owing to the poor histomorphology as well as the occurrence of pancytopenia. The effect of standard chemotherapy is unknown, as survival is limited to a few weeks. This report aimed to evaluate 5 gastric cancer patients with bone marrow metastases to emphasize the importance of this condition.