Impact localization is one of the major concerns in maintenance of aircraft structures built from composites. A lot of different techniques like acoustic emission, optimization technique based on system are nowadays investigated to identify impact location. But the method to identify impact position in complex composite structure with high accuracy in real time has not been completely established. In the present work, a new efficient method is proposed for identifying impact location in real and complex composite structure based on array signal processing and Lamb waves. There are two steps in the proposed method. The first step is to estimate the direction- of-arrival (DOA) of impact source using continuous wavelet transform (CWT) and array signal processing; the second step is to estimate the distance between impact source and the coordinate origin based on propagation characteristic of Lamb wave and CWT. The composite panel with stepped thickness of a real and complex aeronautical tank is used to verify the present methodology. The result shows that the present method may identify impact location fast and accurately.

Rationale:Though it is rare, isolated interrupted aortic arch (IAA) could lead to hypertension. Surgical repair is the only effective curative method to treat IAA conditions and patients with IAA can hardly survive to adulthood with medication alone. We report an IAA case that of a 45-year-old male patient who survived for 45 years without surgical treatment.Patient concerns:A 45-year-old man was referred to the hospital presenting with abnormal blood pressure level. Both computed tomography angiogram (CTA) and angiography revealed IAA.Diagnoses:The patient was diagnosed as IAA based on computed tomography angiogram (CTA) and angiography.Interventions:The patient's blood pressure was severely high and refractory. He refused surgical treatment and accepted antihypertensive medication for 10 days.Outcomes:The patient's office blood pressure level was abnormal, fluctuating between 140/90 and 160/100 mm Hg, but 24-hour ambulatory blood pressure monitoring showed normal level.Lessons:Hypertension due to IAA could be controlled with medications, even surgery is not performed. The discrepancy between ambulatory and office blood pressure levels may be due to the white coat effect.

The gas flow field in hydrocyclone separator was numerically simulated by applying RSM turbulence model, and the gas flow velocity distribution and stress distribution were calculated. According to the characteristics of gas flow distribution within the separator, it is found that: (1) the rotating strength of gas flow is related to the outlet angle of guide blade, the greater the outlet angle, the smaller the tangential velocity; (2) the obvious short circuit flow distribution under the exhaust pipe mouth area is easy to carry droplets and roll them out, causing a decrease in separation efficiency; (3) the high strength of turbulence pulse at mouth area of vent and drainage is easy to break the droplets and decrease their diameter, which affects the separation efficiency. The above research results lay the foundation for the structure optimization and the improvement of separation properties of axial guide vane cyclone gas-liquid separator.