Ciliated Hepatic Foregut Cyst Mimicking a Hydatid Cyst: A Case Report and Review of Literature

A ciliated hepatic foregut cyst is a rare cystic lesion of the liver. A 25-year-old man who was referred from an area endemic for hydatid cysts, presented with abdominal pain. Clinical, paraclinical, and imaging studies all suggested the presence of a hydatid cyst. Pathological studies after the resection of the cyst showed the presence of a ciliated hepatic foregut cyst

Helicopter Blade Stability Analysis Using Aeroelastic Frequency Response Functions

In the present paper, the aeroelastic stability of helicopter rotor blade is determined using Aeroelastic Frequency Response Function. The aeroelastic model of blade is obtained by combining Dowell - Hodges beam model with Loewy unsteady aerodynamic theory which considers an unsteady wake beneath the rotor. Equations are formed and Aeroelastic Frequency Response Functions are obtained by inverting dynamic stiffness matrix of the aeroelastic system. Exciting each degree of freedom, system response could be obtained. The resulted response is then plotted for various blade pitch angles and the behaviour of this function investigated to find out the stability criteria and also system natural frequencies. The results of this method are compared with stability boundaries obtained from the conventional p-k method