    Ð°Ð½ Obstetrician is a physician who has successfully completed specialized education and training in the management of pregnancy, labor, and the puerperium (the t â¦ ime-period directly following childbirth).n Obstetrician specializes in the care and treatment of pregnant women during their pregnancy, labor, delivery and the postpartum period.
Animal skins were used as sails for the earliest boats and rafts. The Egyptians and other ancient people wove reeds together in mats to make sails, but the Egyptians were also the first to make cloth sails as early as 3300 B.C. Great sailors of the Mediterranean region like the Phoenicians sailed under cloth sails.
Several years ago materials as varied as wood, steel and aluminium where used to produce wind blades. The first wind blades where made using wood, a low cost, low density material with a good resistance to fatigue.However, wood has a strong anisotropy and a huge potential variation of his properties, together with a notable tendency to water absorption that can lead to a reduction of resistance.teel was used in the first years of the 80âs in turbines as Growian (Grosse GroÃe â windkraftanlage big wind), turbine A goliath for his times with steel spars and fibreglass. skin