منابع مشابه
Special forms of flight. I: Balloons, gliders, and hang gliders.
Two hundred years ago the Montgolfier brothers first demonstrated to the world that man-carrying "engines for flying" were possible. Their vehicle, however, did not have "artificiall Wings" but was a balloon filled with hot air. (A Brazilian, Bartolomeu de Gusmao, had flown a small unmanned hot air balloon 74 years earlier.') After successful unmanned demonstrations the first recorded free flig...
متن کاملA New Analytical Approach to Flight Equations
The six-degree equations of flight in their classic form do not provide a proper physical perception due to a number of interferences. Nor do they render visible the important role of attack angles. In this study, attempts have been made to develop a complete set of 3D acceleration equations from the equations of normal and tangential acceleration αN=vωv, αt=v ̇. For this purpose, a coordinate s...
متن کاملA New Analytical Approach to Flight Equations
The six-degree equations of flight in their classic form do not provide a proper physical perception due to a number of interferences. Nor do they render visible the important role of attack angles. In this study, attempts have been made to develop a complete set of 3D acceleration equations from the equations of normal and tangential acceleration αN=vωv, αt=v ̇. For this purpose, a coordinate s...
متن کاملCosmic balloons.
Cosmic balloons, consisting of relativistic particles trapped inside a spherical domain wall, may be created in the early universe. We calculate the balloon mass M as a function of the radius R and the energy density profile, ρ(r), including the effects of gravity. At the maximum balloon mass 2GM/R ≈ 0.52 for any value of the mass density of the wall. [email protected] Domain walls may fo...
متن کاملExocrine pancreatic adenocarcinoma in a toy breed dog
A 4-year-old female miniature pincher with a 40-day history of weight loss, lethargy and vomiting was referred to Small Animal Hospital, Faculty of Veterinary Medicine, University of Tehran. The case also had severe jaundice, chronic diarrhoea and steatorrhoea. The efforts for saving the life of the case were not successful and finally the animal died of hypovolaemic shock and electrolyte imbal...
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ژورنال
عنوان ژورنال: Nature
سال: 1930
ISSN: 0028-0836,1476-4687
DOI: 10.1038/126919d0