the depth control systems used in iranian tractors are mechanical and they produce variable tillage depth in uneven field surface. in this research a rotary type electronic control valve was designed and constructed. by using this valve, electro-hydraulic tillage depth control system was developed and installed on the tractor. the control system was composed of: a depth sensor, a programmable l...

the bicuspid aortic valve is known to be the most common congenital cardiac malformation, with an approximate incidence rate of 1-2% in the general population. most patients are unaware of the disease until the onset of infective endocarditis, which is a life-threatening complication that may affect a heart valve or other cardiac structures at the site of endothelial damage. a 22-year-old man p...

abstract background: few attempts were made for alleviating the physical/psychological problems among the cardiac valve–replaced patients and no comprehensive study was done based on the experiences of such patients. this study was undertaken to describe the stressful experiences of the heart valve-replaced patients. materials and methods: in this qualitative study performed during 2012-2013 wi...

in this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in xu7/l3 engine. in this study, considering the strength and accuracy of simulation gt-power software in researches on the internal combustion engine...

BACKGROUND Kearns-Sayre Syndrome (KSS) is a multisystem disorder caused by a dysfunction of the oxidative phosphorylation system within mitochondria. Mitochondrial DNA (mtDNA) rearrangements are a key molecular feature of this disease, which manifest a broad phenotypic spectrum. CASE PRESENTATION Here, we present a boy with KSS whose symptoms included cardiac conduction deficit, cardiomyopath...

The "push-pull" effect denotes the reduced tolerance to +Gz (hypergravity) when +Gz stress is preceded by exposure to hypogravity, i.e., fractional, zero, or negative Gz. Previous studies have implicated autonomic reflexes as a mechanism contributing to the push-pull effect. The purpose of this study was to test the hypothesis that nonautonomic mechanisms can cause a push-pull effect, by using ...

Herein, we present the case of a 10-year-old child suffering from right-sided infective endocarditis with ventricular septal defect. Echocardiography revealed multiple rare large vegetations on the pulmonary valve extending into pulmonary artery along with a large vegetation over the septal leaflet of the tricuspid valve. 

Rheumatismal lesions of the mitral valve a!I'e rare under the age of six and surgical iruter­vention in symptomatic patients is an academic problem. Early surgical treatment has been done to prevent serious changes and unrevers­ib1e complications o.f the heart and lungs.  From April 71 until April 74, thirty-five pati­ent, ranging between 8-18 years of age, suffer­ing of <lifferents heart ,tro...