the hot compression tests were carried on x45crniw189 valve steel (x45) in the temperature rangeof 1000– 1200 °c and the strain rate range of 0.004 – 0.5 s-1 in order to study the high temperaturesoftening behavior of this steel. for the exact prediction of flow stress, the effective stress-effectivestrain curves were obtained from experiments under various conditions. on the basis of experimen...

in this paper robust pid control of fully-constrained cable driven parallel manipulators with elastic cables is studied in detail. in dynamic analysis, it is assumed that the dominant dynamics of cable can be approximated by linear axial spring. to develop the idea of control for cable robots with elastic cables, a robust pid control for cable driven robots with ideal rigid cables is firstly de...

granulocytic sarcomas (chloromas) are rare extramedullary tumors consisting of primitive granulocytic cells. we report here on a case of a 23-year-old man who presented with a generalized swelling. he is known case of acute myelomonocytic leukemia. granulocytic sarcomas are rare, destructive, extramedullary tumor masses that consist of immature granulocytic cells. in this unusual patient's case...

multiple aorto-cardiac cavity communications is very rare but important complication of prosthetic aortic valve endocarditis. the case below illustrates multiple aorto-cardiac cavity fistula formation following prostethic aortic valve endocarditis presented with slowly progressive symptoms of heart failure. a brief review of surgical reconstruction and the existing literature are presented, inc...

background: the adult cardiac surgery databank (acsd) of tehran heart center was established in 2002 with a view to providing clinical prediction rules for outcomes of cardiac procedures, developing risk score systems, and devising clinical guidelines. this is a general analysis of the collected data. methods: all the patients referred to tehran heart center for any kind of heart surgery betwee...

giant left atria are defined as those measuring larger than 8 cm and are typically found in patients who have rheumatic mitral valve disease with severe regurgitation. enlargement of the left atrium may create compression of the surrounding structures such as the esophagus, pulmonary veins, respiratory tract, lung, inferior vena cava, recurrent laryngeal nerve, and thoracic vertebrae and lead t...

background: about half of all patients who undergo mitral valve surgery suffer from atrial fibrillation (af). cox described the surgical cut-and-sew maze procedure, which is an effective surgical method but has some complications. this study was designed to evaluate the efficacy of a substitution method of radiofrequency ablation (rfa) for patients undergoing mitral valve surgery with af. metho...

the grace mission has provided scientific community time-variable gravity field solutions with high precision and on a global scale. the grace mission was launched on march 2003. this mission consists of two satellites that pursue each other in their orbit. distance between two satellites in orbit is measured continuously to an accuracy of better than 1 micron using kbr system placed in satelli...