Improving aerodynamic models for adverse loss-of-control conditions in flight is an area being researched under the NASA Aviation Safety Program. Aerodynamic models appropriate for loss of control conditions require a more general mathematical representation to predict nonlinear unsteady behaviors. As more general aerodynamic models are studied that include nonlinear higher order effects, the p...

This paper discusses the influence of aerodynamic drag torque on the dynamics of a satellite in a very low altitude orbit. The larger atmospheric density in low altitude earth orbits results in significant aerodynamic drag torques acting on the satellite. With a conventional satellite design this may result in instability. This paper shows how the instability can be avoided, and how the aerodyn...

[1] The aerodynamic friction between air and sea is an important part of the momentum balance in the development of tropical cyclones. Measurements of the drag coefficient, relating the tangential stress (frictional drag) between wind and water to the wind speed and air density, have yielded reliable information in wind speeds less than 20 m/s (about 39 knots). In these moderate conditions it i...

This paper presents a method of transforming aerodynamic datasets generated in Aerodynamic Preliminary Analysis System (APAS) into parametric equations which may subsequently be used in a multidisciplinary design optimization (MDO) environment for analyzing aerospace vehicles. APAS is an analysis code which allows the user to create a simple geometric model of a vehicle and then calculate the a...

  Background: Increased oxygen free radical and reduced glutathione level in the eye lens are important risk factor for cataract formation. The antioxidative property and increasing cellular and extra cellular glutathione level have been reported by several herbal medicines including silymarin.  Objective: In present interventional study Silybum marianum L. seed extract (silymarin) was tested a...

This paper focuses on the demonstration of an integrated aero-structural method for the design of aerospace vehicles. Both aerodynamics and structures are represented using high-fidelity models such as the Euler equations for the aerodynamics and a detailed finite element model for the primary structure. The aerodynamic outer mold line (OML) and a structure of fixed topology are parameterized u...

NASA’s Hyper-X Research Vehicle will provide a unique opportunity to obtain data on an operational airframe integrated scramjet propulsion system at true flight conditions. The airframe integrated nature of the scramjet engine with the Hyper-X vehicle results in a strong coupling effect between the propulsion system operation and the airframe’s basic aerodynamic characteristics. Comments on gen...

The development and application of model reduction techniques have been widely investigated for problems in unsteady aerodynamic systems, driven mainly by the need to develop effective economical computational models capturing as much flow physics as possible. These techniques which have been based on a number of approaches such as balanced truncation, Arnoldi, proper orthogonal decomposition e...

Introduction: Critical organs and structures may receive significant amounts of irradiation even if they are not the target of radiotherapy or located outside the treatment field. Although the sensitive thyroid gland and lens are not directly the targets of treatment, they can be affected by irradiation during the treatment of tumours in head and neck region. The purpose of thi...

Introduction: Among the components of the extracellular matrix (ECM) and basement membrane (BM), laminitis heterotrimeric glycoprotein (laminin) and collagen type IV are the most important. In a previous study we have examined the role of collagen type IV in the developing lens capsule. The present study aims to determine the appearance and distribution of laminin in the BM and ECM of lenses ...