29 research outputs found
Historical biogeography and modes of speciation across high-latitude seas of the Holarctic: concepts for host – parasite coevolution among the Phocini (Phocidae) and Tetrabothriidae (Eucestoda)
Lower-Order Aerodynamic Loads Modeling of a Maneuvering Generic Fighter Using DDES Simulations
Unforeseen nonlinear aerodynamic behavior and/or fluid-structure interactions have affected the development of nearly every major fighter program since 1960. The development cost of each of these aircraft could have been drastically reduced if these aerodynamic issues had been identified earlier in the design process. Therefore, a high-fidelity computational tool capable of reliably predicting or identifying configurations susceptible to handling quality instabilities prior to flight test would be of great interest to the stability and control community. The United States Air Force Academy Modeling and Simulation Research Center and the United States Air Force Seek Eagle Office have initiated a joint effort to develop nonlinear lower-order aerodynamic loads models from unsteady CFD solutions. A key step in the process is to perform “training maneuvers,” which are dynamic CFD simulations designed to excite the relevant nonlinear flow physics. A reduced-order model is then built using SIDPAC, a regression based modeling technique designed specifically for aircraft system identification. The approach is validated for an aircraft configuration with a known aerodynamic instability that occurs well within the flight envelope. The dynamic CFD simulations can reliably predict this instability for frequencies ranging from 1.43 to 17.1 Hertz. In addition, an aerodynamic model trained using a varying frequency chirp maneuver was then used to predict constant frequency aerodynamic loads at conditions where strongly nonlinear aerodynamic behavior occurred
Diet and feeding observations from an unusual beluga harvest in 2014 near Ulukhaktok, Northwest Territories, Canada
Financial Valuation Algorithm for the Assessmentof the Future Sales of a New, Innovative Medicinal Product
Nephelometry v differential agglutination titre in the measurement of rheumatoid factors.
Antioxidant and anti-inflammatory effects of dimethyl fumarate in hypercholesterolemic rabbits
Ascorbic, Dehydroascorbic and Isoascorbic Acid Simultaneous Determinations By Reverse Phase Ion Interaction Hplc
Detection was by UV absorbance (after pre-column derivatization of dehydroascorbic acid with 1,2-phenylenediamine). When absent, isoascorbic acid could be used as internal standard. Isocratic separation was accomplished in 11 min using the eluent, methanol-water (5:95, v/v) containing potassium dihydrogen phosphate (50 mM) and the counterion hexadecyltrimethylammonium bromide (5 mM). Sample preparation steps using Sep-pak C18 cartridge were minimal. Ten ppm could be detected for each compound with good reproducibility (c.v. < 2%). The method was used to determine vitamin C content in selected foods and beverages